Automotive engineers and technicians work with English every day: workshop manuals, diagnostic software, supplier specifications, test reports and recall notices are very often written in it. Knowing the core words for engines, transmissions, electric vehicles, brakes, electronics, production and dealership work helps you read technical documents, explain a fault clearly and work smoothly with international teams and suppliers.
100 terms
9 topics
49 core terms
200 example sentences
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No account needed. Read the meaning, see where the term is used, then study the examples. Click any word in the lesson for help. You can also select a word and press Alt + Enter.
Engine and Fuel Systems
engine
noun
Meaning
The machine that burns fuel, usually petrol or diesel, to produce the power that moves a vehicle. It turns the energy of burning fuel into rotation of the crankshaft.
Where you use it
One of the most common words in any workshop or engineering office. You start, run, rebuild or tune an engine; people talk about engine size (for example a 1.6-liter engine), the engine bay, engine oil and engine noise.
Examples
The engine starts fine but runs rough for the first few minutes on cold mornings.
This model is available with a 1.5-liter petrol engine or a diesel engine.
Usage note
Engineers say engine for a combustion engine and motor for an electric motor. Turkish uses motor for both, so 'electric engine' sounds wrong in English; say electric motor.
Common phrases
start the engine · diesel engine · engine bay · engine oil · engine rebuild
Twisting force, measured in newton meters (Nm) or pound-feet. It describes how strongly an engine or motor turns, and how tightly a bolt should be tightened.
Where you use it
Two everyday meanings: engine torque (for example 250 Nm at 1,500 rpm) and tightening torque in repair manuals. It is also a verb: torque the wheel nuts to 120 Nm. Torque spec means the specified value.
Examples
The diesel engine produces 400 Nm of torque from just 1,750 rpm.
Torque the cylinder head bolts in three stages, following the sequence in the manual.
A unit of engine power. One mechanical horsepower is about 746 watts, and the metric horsepower (PS) used in Europe is about 735 watts. Many specifications also give power in kilowatts (kW).
Where you use it
Used in brochures, reviews and spec sheets, often shortened to hp. People talk about how much horsepower a car makes and quote it with an engine speed, for example 150 hp at 6,000 rpm.
Examples
The facelift model gets 20 more horsepower and a new eight-speed gearbox.
On the dyno, the car made 182 horsepower at the wheels.
An electrically controlled valve that sprays a precise amount of fuel into the engine at the right moment. The ECU decides how long each injector stays open.
Where you use it
Technicians test, clean, code and replace fuel injectors; common faults are leaking, sticking or clogged injectors. Modern engines use direct injection (into the cylinder) or port injection (into the intake port).
Examples
Cylinder three misfires because its fuel injector is leaking.
New diesel fuel injectors must be coded to the ECU after fitting.
An engine that burns fuel and air inside its cylinders, so the pressure of the hot gas pushes the pistons. Petrol and diesel car engines are both of this type.
Where you use it
Often shortened to ICE, especially when comparing conventional cars with electric ones: ICE vehicles, ICE versions, the end of ICE sales. In everyday workshop talk people simply say engine.
Examples
The platform was designed for both electric and internal combustion engine versions.
A typical internal combustion engine works on a four-stroke cycle: intake, compression, power and exhaust.
Common phrases
ICE vehicle · internal combustion engine car · phase out internal combustion engines · four-stroke engine
One of the round chambers in an engine block where a piston moves up and down and the fuel is burned. Most car engines have three, four or six cylinders.
Where you use it
Engines are described by the number and layout of cylinders: a four-cylinder, an inline six, a V8. Technicians do a compression test on each cylinder; the cylinder head sits on top of the cylinder block.
Examples
Compression in cylinder two is much lower than in the other cylinders.
The new 1.0-liter engine has three cylinders and a turbocharger.
Common phrases
cylinder head · cylinder block · four-cylinder engine · cylinder bore · compression test
A short metal cylinder that moves up and down inside an engine cylinder. The force of combustion pushes it down, and a connecting rod passes this movement to the crankshaft.
Where you use it
Used in engine design and rebuilds. Engineers talk about piston rings, piston crown and piston stroke; technicians look for piston damage, worn rings and oil consumption after an engine failure.
Examples
The piston crown in cylinder four has a hole burned through it.
Worn piston rings are the most likely cause of the high oil consumption.
Usage note
Turkish workshops call piston rings segman; in English they are piston rings, never 'segments'.
The main rotating shaft at the bottom of an engine. It turns the up-and-down movement of the pistons into rotation that drives the gearbox.
Where you use it
Often shortened to crank. You hear crankshaft position sensor, crankshaft pulley and crankshaft seal. Engine speed (rpm) is the number of crankshaft turns per minute, and 'crank the engine' means turn it with the starter.
Examples
The engine cranks but won't start, so check the crankshaft position sensor signal.
Oil is leaking from the rear crankshaft seal onto the clutch.
Common phrases
crankshaft position sensor · crankshaft pulley · crankshaft seal · crank the engine
A shaft with shaped lobes (cams) that opens and closes the engine valves at the right time. It is driven by the crankshaft through a timing belt or chain.
Where you use it
Common in engine specs and repair manuals. A DOHC engine has two overhead camshafts per cylinder bank; variable valve timing changes camshaft timing while the engine runs. The related sensor is the camshaft position sensor.
Examples
The timing marks on the camshaft and crankshaft must line up before you fit the new belt.
Code P0016 means the camshaft and crankshaft signals don't match.
A device that uses the flow of exhaust gas to spin a turbine, which drives a compressor that pushes more air into the engine. More air allows more fuel to be burned and more power to be produced.
Where you use it
Usually just called a turbo. People talk about boost pressure, turbo lag and the intercooler. Small turbocharged petrol engines replaced many larger engines to cut fuel use and emissions (downsizing).
Examples
The turbocharger is whistling and the car has lost power, so check the intake hoses for leaks.
Let the engine idle for a moment after hard driving so the turbocharger can cool down.
Common phrases
boost pressure · turbo lag · turbocharged engine · replace the turbocharger
A part of the exhaust system that uses precious metals such as platinum, palladium and rhodium to turn harmful gases (CO, HC and NOx) into less harmful ones before they leave the car.
Where you use it
Often called a cat. Technicians check catalytic converter efficiency with the oxygen sensors; a failing cat sets codes such as P0420. Because of the metals inside, catalytic converters are a common target for theft.
Examples
The catalytic converter is partly blocked, which explains the loss of power.
Misfires can overheat and damage the catalytic converter.
The gases and particles a vehicle releases, mainly from the exhaust, such as CO2, NOx and soot. Their limits are set by regulations such as the Euro 6 standard.
Where you use it
Usually plural. Engineers work on emissions compliance and emissions testing; regulators set emissions limits; cars must pass an emissions test at periodic inspection. CO2 emissions are given in g/km.
Examples
The new engine meets Euro 6 emissions limits in real-driving tests as well as in the lab.
The car failed the emissions test because of a faulty oxygen sensor.
Common phrases
emissions standards · CO2 emissions · emissions test · tailpipe emissions · reduce emissions
The liquid, usually water mixed with antifreeze, that flows through the engine and radiator to carry heat away. It also protects against freezing and corrosion.
Where you use it
Technicians check the coolant level, top up or flush the coolant and look for coolant leaks. Coolant temperature is one of the key values on a scan tool. Electric vehicles also use coolant to control battery temperature.
Examples
The coolant level keeps dropping, but there's no visible leak.
Never open the coolant cap while the engine is hot.
Usage note
In English antifreeze is the concentrate and coolant is the ready mixture in the system. Turkish workshops usually call both antifriz.
Common phrases
coolant level · coolant leak · coolant temperature · top up the coolant · coolant flush
How much fuel a vehicle uses to travel a given distance. In Europe and Turkey it is given in liters per 100 km; in the US it is given in miles per gallon (mpg).
Where you use it
Used in brochures, reviews and engineering targets. People compare official (WLTP) figures with real-world fuel economy. In British and European documents the term fuel consumption is more common.
Examples
The hybrid's fuel economy in city driving is about 4.5 liters per 100 km.
Low tire pressure can make fuel economy noticeably worse.
Usage note
With L/100 km a lower number is better; with mpg a higher number is better. So 'better fuel economy' means a lower L/100 km figure.
A toothed rubber belt that keeps the crankshaft and camshafts turning in exact time, so the valves open and close at the right moment. Some engines use a timing chain instead.
Where you use it
Replaced at the interval set by the manufacturer, usually together with the tensioner and idlers as a timing belt kit, and often the water pump. On many engines a broken belt lets the pistons hit the valves and causes serious damage.
Examples
The timing belt is due at 120,000 km or six years, whichever comes first.
The timing belt snapped on the motorway and bent four valves.
Usage note
Turkish 'triger' comes from French. In English, say timing belt or timing chain; 'trigger' means something completely different.
Common phrases
timing belt kit · timing belt replacement · timing chain · broken timing belt
A part screwed into the cylinder head of a petrol engine that makes an electric spark to ignite the fuel and air mixture. Diesel engines do not have spark plugs.
Where you use it
Technicians remove, inspect, gap and replace spark plugs at service intervals. Worn or fouled plugs cause misfires and hard starting. Each plug is fed by an ignition coil, often one coil per cylinder.
Examples
The spark plug from cylinder one is black and sooty, so the mixture is too rich.
Replace the spark plugs every 60,000 km on this engine.
Usage note
Diesel engines use glow plugs (kızdırma bujisi) to help cold starts. In Turkish both are called buji, but in English they are different parts.
Common phrases
replace the spark plugs · spark plug gap · fouled spark plug · ignition coil
To run with the engine on but the car not moving and the accelerator not pressed, at a low, steady engine speed. As a noun, idle is this state.
Where you use it
Very common in diagnosis: the engine idles at 750 rpm, rough idle, idle speed, high idle. Technicians check live data at idle and under load. Start-stop systems switch the engine off instead of letting it idle at traffic lights.
Examples
The engine idles rough until it reaches normal temperature.
Idle speed is too high, so check for a vacuum leak.
Usage note
Turkish rölanti comes from French, so the English word looks nothing like it. Idle sounds exactly like idol (a person people admire), so take care with the spelling.
Common phrases
rough idle · idle speed · at idle · high idle · let the engine idle
For an engine to stop running suddenly while the car is in use, for example when the driver releases the clutch too fast or because of a fault.
Where you use it
Used by drivers and technicians: the engine stalls, the car stalled at the lights, I stalled it. A customer complaint like 'stalls when coming to a stop' points to idle control, fuel supply or sensor faults.
Examples
The engine stalls when the air conditioning is switched on at idle.
Learner drivers often stall the car on hill starts.
Usage note
Turkish drivers say 'stop etmek', but in English 'the engine stopped' sounds neutral, while 'the engine stalled' means it stopped unexpectedly.
Common phrases
engine stalls · stall the car · stall at idle · stalling problem
All the parts that create power and deliver it to the road wheels: the engine or electric motor, the transmission, the driveshafts and the differential.
Where you use it
Common in engineering, product planning and warranty documents. Car makers have powertrain departments and powertrain engineers; you also hear electrified powertrain, hybrid powertrain and powertrain warranty.
Examples
The powertrain team is testing the new hybrid system on the dyno this week.
The powertrain warranty covers the engine and gearbox for five years.
Usage note
Powertrain usually includes the engine; drivetrain usually means everything after the engine. People often mix them up, so check how a document defines them.
The unit that changes the gear ratio between the engine and the wheels so the car can pull away, accelerate and cruise efficiently. It can be manual or automatic.
Where you use it
Used in sales, service and engineering. Common types are manual, automatic, CVT and dual-clutch (DCT). Technicians talk about transmission fluid, slipping and harsh shifts. British speakers often say gearbox.
Examples
The customer says the automatic transmission slips when it shifts from second to third.
We flushed the transmission fluid and updated the software, and the harsh shifts are gone.
Usage note
In US English transmission is the everyday word; in UK English gearbox is more common. Both mean şanzıman.
The part that connects and disconnects the engine and the gearbox, so the driver can change gear and pull away smoothly. In a manual car it is operated with the left pedal.
Where you use it
Drivers press and release the clutch; technicians replace clutch kits and diagnose a slipping clutch. Dual-clutch automatic transmissions (DCT) use two clutches that the car controls itself.
Examples
The clutch slips in fourth gear, so it needs replacing.
We replaced the clutch kit and the dual-mass flywheel at the same time.
Usage note
The Turkish word debriyaj comes from French; the English word is clutch. What Turkish workshops call 'baskı balata' is the clutch kit (pressure plate and clutch disc).
The number of turns the input shaft makes for one turn of the output shaft, for example 3.5:1. Low gears have high ratios for pulling power; high gears have low ratios for cruising.
Where you use it
Used in transmission and powertrain engineering. Engineers choose the gear ratios and the final drive ratio; people describe gearing as short (quick acceleration) or long (low rpm on the highway). 3.5:1 is read 'three point five to one'.
Examples
We changed the final gear ratio to lower engine speed at 120 km/h.
First gear has a ratio of 3.7:1, while sixth gear has a ratio of 0.7:1.
Common phrases
final drive ratio · short gear ratio · gear ratio spread · change the gear ratio
A gear set on a driven axle that lets the left and right wheels turn at different speeds when the car goes around a corner, while still sending power to both.
Where you use it
Often shortened to diff. Technicians change differential oil and diagnose whining noises from the diff. A limited-slip differential (LSD) reduces wheel spin; all-wheel-drive cars may have a center differential too.
Examples
There's a whining noise from the rear differential above 80 km/h.
The performance model comes with an electronically controlled limited-slip differential.
A drive system that can send engine or motor power to all four wheels, usually controlled automatically to improve grip on wet, icy or loose roads.
Where you use it
Shortened to AWD and compared with front-wheel drive (FWD) and rear-wheel drive (RWD). It is also used as an adjective: an all-wheel-drive SUV. Many electric cars get AWD by adding a second motor on the other axle.
Examples
The all-wheel drive version is popular with customers in the eastern provinces.
The dual-motor model has all-wheel drive and a 0-100 km/h time of 4.5 seconds.
Usage note
AWD and 4WD both mean dört çeker in Turkish, but in English 4WD usually means a tougher off-road system with a transfer case and low-range gears.
Common phrases
all-wheel-drive system · permanent all-wheel drive · AWD version · front-wheel drive
A shaft or beam on which a pair of wheels is mounted. A drive axle also transmits power to the wheels; a non-driven axle only carries the weight.
Where you use it
Common phrases are front axle, rear axle, axle load and axle shaft. Parts such as brake pads and tires are replaced in axle sets, meaning both sides of the same axle together.
Examples
Always replace brake pads on both sides of the axle at the same time.
A rotating shaft that carries torque from the gearbox towards the wheels. In rear-drive cars it is the long shaft to the rear axle; in front-drive cars short driveshafts run to each front wheel.
Where you use it
Also written drive shaft. Technicians check driveshafts for vibration, worn universal joints and torn CV joint boots; a clicking noise when turning often means a worn CV joint on the driveshaft.
Examples
The clicking on full lock comes from the left driveshaft's outer CV joint.
A bent driveshaft causes vibration that gets worse with speed.
Usage note
In US English the long shaft to the rear axle is the driveshaft (Turkish: kardan mili). In UK English it is usually the propshaft, and drive shafts are the short shafts to the wheels (aks mili).
A vehicle driven only by one or more electric motors that take energy from a rechargeable battery. It has no fuel tank and produces no exhaust emissions while driving.
Where you use it
Usually shortened to EV in speech and writing. People also say BEV (battery electric vehicle) to separate it from hybrids. Common topics are EV charging, EV range and the battery warranty.
Examples
Our service center needs two more technicians certified to work on electric vehicles.
Electric vehicles need much less routine maintenance because there is no engine oil to change.
Common phrases
battery electric vehicle · EV charging · EV range · EV adoption
The large high-voltage battery that stores energy for an electric or hybrid vehicle. It is made of many cells grouped into modules, with cooling and control electronics in one housing.
Where you use it
Engineers talk about pack capacity in kWh, pack voltage (often 400 V or 800 V) and pack cooling. Only trained technicians may open or replace a battery pack, after the high-voltage system has been safely isolated.
Examples
The battery pack has a usable capacity of 77 kWh.
A damaged battery pack must be stored outside, away from other vehicles.
Usage note
Turkish workshops say akü for the 12 V starter battery and batarya for the high-voltage pack. In English both are battery, so add 12 V or high-voltage to be clear.
Equipment that supplies electricity to recharge an electric or plug-in hybrid vehicle. It can be a wall box at home, a public AC charger or a high-power DC fast charger.
Where you use it
Also called a charger or charge point; the technical name is EVSE (electric vehicle supply equipment). Drivers find, plug in and pay at charging stations; dealers install them for customers and for their service bays.
Examples
The nearest DC charging station is 40 kilometers away on the highway.
The dealership installed four charging stations for its demo cars.
Common phrases
public charging station · home charging station · fast charging station · charging network
A way of slowing an electric or hybrid vehicle in which the electric motor works as a generator, turning the car's movement back into electricity that is stored in the battery.
Where you use it
Often called regen. Drivers choose regen levels, and strong regen allows one-pedal driving. Because regen does much of the slowing, EV brake pads last longer, but the discs can corrode from lack of use.
Examples
Regenerative braking recovered about 15 percent of the energy on the city test route.
When the battery is full, regenerative braking is limited, so the car feels different on long descents.
The distance a vehicle can travel on a full battery or a full tank. For electric cars it is usually given according to an official test cycle such as WLTP.
Where you use it
Usually just range in conversation. People compare official (WLTP) range with real-world range; cold weather, high speed and heating reduce it. Range anxiety is the fear of running out of charge before reaching a charger.
Examples
The official driving range is 520 km, but expect around 400 km on the highway in winter.
Using the heat pump instead of the resistive heater improves driving range in cold weather.
Common phrases
WLTP range · real-world range · range anxiety · extend the range
How full a battery is at a given moment, shown as a percentage of its usable capacity. The battery management system estimates it continuously.
Where you use it
Engineers write SOC or SoC. Charging speed depends on it: DC fast charging is quickest at low SOC and slows down above about 80%. It is different from state of health (SOH), which shows how much the battery has aged.
Examples
The car arrived at the charger with a state of charge of 12 percent.
For long-term storage, keep the battery at a state of charge of around 50 percent.
Common phrases
SOC window · low state of charge · target state of charge · state of health
Short for battery management system: the electronics that monitor the voltage, current and temperature of the cells, keep them balanced and protect the battery from overcharging, deep discharge and overheating.
Where you use it
Used by battery and software engineers and EV technicians. The BMS estimates state of charge and state of health, limits charging and discharging power, and stores fault codes that a scan tool can read.
Examples
The BMS reduced charging power because the cell temperatures were too low.
A BMS software update improved the accuracy of the range estimate.
The electric motor that drives the wheels of an electric or hybrid vehicle. Most modern cars use permanent magnet synchronous motors, though induction motors are also used.
Where you use it
In everyday speech people say the electric motor or simply the motor; traction motor is the engineering term. Engineers talk about motor power, peak and continuous torque and motor efficiency. Many EVs combine the motor, inverter and gearbox in one drive unit.
Examples
The rear traction motor delivers 210 kW and 400 Nm.
We are testing a traction motor that uses no rare-earth magnets.
Common phrases
permanent magnet motor · electric drive unit · front traction motor · motor efficiency
Power electronics that convert direct current (DC) from the battery into alternating current (AC) for the traction motor, controlling its speed and torque. During regenerative braking it works the other way.
Where you use it
Used by power electronics and powertrain engineers. Common topics are inverter efficiency, inverter cooling and silicon carbide (SiC) switches, which reduce losses, especially in 800 V systems.
Examples
The new silicon carbide inverter cut losses by almost a third.
An inverter fault put the car into limp mode with reduced power.
A vehicle that combines a combustion engine with one or more electric motors and a battery. A full hybrid charges its battery from the engine and from regenerative braking, not from a plug.
Where you use it
Often shortened to HEV. People distinguish mild hybrids (usually a 48 V system that assists the engine), full hybrids (can drive short distances on electric power) and plug-in hybrids (charged from the grid).
Examples
Our hybrid vehicle drives on electric power at low speeds in city traffic.
Technicians must complete high-voltage training before working on a hybrid vehicle.
Common phrases
full hybrid · mild hybrid · hybrid system · hybrid powertrain
A hybrid with a larger battery that can be charged from a socket or charging station, so it can drive a useful distance, often 40 to 100 km, on electric power alone.
Where you use it
Shortened to PHEV. Its official fuel consumption is very low, but real use depends on how often the driver charges. People talk about electric range, EV mode and charge-sustaining mode.
Examples
The plug-in hybrid has an electric range of 75 km, enough for most daily commutes.
If you never charge a plug-in hybrid, it uses more fuel than a normal hybrid because of the extra weight.
Common phrases
plug-in hybrid electric vehicle · electric range · EV mode · charge the plug-in hybrid
High-power charging in which the charging station supplies direct current straight to the battery, bypassing the car's on-board charger. Typical power ranges from 50 kW to over 300 kW.
Where you use it
Compared with slower AC charging at home or work. Charging speed is highest at a low state of charge and drops as the battery fills, so manufacturers quote times such as 10 to 80 percent in 25 minutes. In Europe the usual connector is CCS2.
Examples
With DC fast charging, the battery goes from 10 to 80 percent in about 30 minutes.
In cold weather, precondition the battery before DC fast charging to get full power.
Common phrases
DC fast charger · peak charging power · charging curve · AC charging
A dangerous chain reaction in a lithium-ion cell in which rising temperature causes reactions that release even more heat, which can lead to fire, toxic gases and spread to neighboring cells.
Where you use it
Used in battery safety engineering and EV damage handling. Causes include internal short circuits, crash damage, overcharging and overheating. Engineers design packs to detect and delay propagation from one cell to the next.
Examples
The test showed that thermal runaway in one cell did not spread to the rest of the module.
After a serious crash, the battery is monitored for 48 hours because of the risk of thermal runaway.
Common phrases
thermal runaway propagation · risk of thermal runaway · cell venting · battery fire
The smallest electrochemical unit of a battery. Many cells are connected into modules and packs; the main formats are cylindrical, prismatic and pouch cells.
Where you use it
Battery engineers talk about cell chemistry (such as NMC or LFP), cell voltage, cell balancing and cell suppliers. A typical lithium-ion cell has a nominal voltage of about 3.2 to 3.7 V, depending on chemistry.
Examples
One battery cell in module 6 is 50 mV lower than the others.
The new model switches to LFP battery cells for the standard-range version.
A device that slows or stops a vehicle by pressing a friction material against a rotating disc or drum. Most cars have hydraulic disc brakes at the front.
Where you use it
Usually plural when talking about the system: check the brakes, the brakes are squeaking. Common phrases are apply the brakes, brake pedal, brake fluid and parking brake. It is also a verb: brake hard, brake early.
Examples
The brakes squeal at low speed, so I'll check the pads and discs.
The driver braked hard, but the car still pulled to the left.
Usage note
Do not confuse brake (fren) with break (kırmak, mola). They sound exactly the same, so the spelling matters in reports.
Common phrases
brake pedal · brake fluid · parking brake · apply the brakes · brake hard
The system of springs, shock absorbers and linkages that connects the wheels to the body. It absorbs bumps and keeps the tires in contact with the road.
Where you use it
Engineers talk about suspension design, setup and geometry; technicians inspect suspension components for wear and knocking noises. Common types are MacPherson strut, double wishbone and multi-link.
Examples
There's a knocking noise from the front suspension when the car goes over speed bumps.
The sports version has a stiffer suspension and a lower ride height.
The system that lets the driver turn the front wheels to change direction, from the steering wheel through the column and the rack to the wheels.
Where you use it
Used for both the system and how it feels. Drivers complain of heavy, loose or vibrating steering; technicians check the steering rack, tie rods and steering angle sensor. The round part you hold is the steering wheel.
Examples
The steering feels heavy at parking speeds.
We replaced the tie rod ends because there was play in the steering.
Usage note
In Turkish direksiyon means both the system and the wheel you hold. In English the wheel is the steering wheel; steering alone means the system or how it feels.
The rubber cover fitted around a wheel rim that grips the road and carries the weight of the vehicle. Most car tires are filled with air.
Where you use it
Common verbs are fit, rotate, inflate and replace. You read the tire size on the sidewall (for example 205/55 R16) and check tire pressure; seasonal changes are between summer and winter tires.
Examples
The rear left tire has a slow puncture, so it loses pressure overnight.
We fitted the winter tires and set the pressure to 2.3 bar.
Usage note
US English writes tire; UK English writes tyre. Both mean lastik. Turkish 'lastik' can also mean the material, but in English the material is rubber and the part is the tire.
A steel plate with a layer of friction material that the caliper presses against the brake disc to slow the wheel. Pads wear down and must be replaced regularly.
Where you use it
One of the most common service jobs. Technicians measure pad thickness, replace pads in axle sets and bed in new pads. A wear indicator, either a sensor or a small metal tab, warns when the pads are low.
Examples
The front brake pads are down to 3 mm, so I recommend replacing them now.
Avoid hard braking for the first 200 km while the new pads bed in.
Common phrases
replace the brake pads · pad wear sensor · worn brake pads · bed in the pads
The metal disc that turns with the wheel and is squeezed by the brake pads to slow the car. Its minimum thickness is usually stamped on the disc itself.
Where you use it
Technicians measure disc thickness and runout, and replace or skim (machine) discs. Uneven discs cause vibration through the pedal or steering wheel when braking; people often call them warped discs.
Examples
The brake discs are below minimum thickness and must be replaced with the pads.
The steering wheel shakes under braking, which points to uneven front brake discs.
Usage note
American manuals usually say brake rotor; British and European ones say brake disc. Both mean fren diski.
Short for anti-lock braking system: it stops the wheels from locking under hard braking, so the driver can still steer. Wheel speed sensors tell the ABS unit when a wheel is about to lock.
Where you use it
Drivers notice ABS as a pulsing brake pedal and a buzzing noise in an emergency stop. Technicians deal with the ABS warning light, the ABS module (pump and valve unit) and faulty wheel speed sensors. Stability control (ESC) builds on ABS.
Examples
The ABS light came on after the car went through deep water.
A pulsing pedal during an emergency stop is normal; it means the ABS is working.
A hydraulic part of the suspension that controls how fast the springs compress and rebound, so the car does not keep bouncing after a bump.
Where you use it
Often called shocks; engineers usually say damper. Technicians look for leaking or worn shock absorbers and replace them in pairs. In a MacPherson strut the spring and shock absorber form one unit.
Examples
The rear shock absorbers are leaking oil and need replacing.
Worn shock absorbers make the car bounce and increase braking distance.
Common phrases
leaking shock absorber · front shock absorbers · replace the shocks · adaptive dampers
The adjustment of the wheel angles (toe, camber and caster) to the manufacturer's values, so the car drives straight and the tires wear evenly.
Where you use it
Done on an alignment machine after replacing suspension or steering parts, or when the car pulls to one side. Technicians check, adjust and print out the alignment readings before and after.
Examples
The car pulls to the right, so we'll do a wheel alignment after we fit the new tie rods.
Poor wheel alignment has worn the inner edges of both front tires.
Usage note
Turkish workshops often say 'rot balans' as one job, but they are two different things: wheel alignment is rot ayarı, and wheel balancing (removing vibration with small weights) is balans ayarı.
Common phrases
four-wheel alignment · check the wheel alignment · alignment machine · out of alignment
A system that reduces the effort needed to turn the steering wheel, using either a hydraulic pump and fluid or, in most modern cars, an electric motor (EPS).
Where you use it
Technicians deal with power steering fluid leaks, a whining pump, or an EPS fault that suddenly makes the steering heavy. Electric power steering also allows lane keeping and parking assist to steer the car.
Examples
The power steering pump whines on full lock, and the fluid level is low.
An electric power steering fault left the driver with very heavy steering.
Common phrases
electric power steering · power steering fluid · power steering pump · loss of power steering
The housing with one or more hydraulic pistons that sits over the brake disc and squeezes the brake pads against it when the driver presses the pedal.
Where you use it
Technicians clean and lubricate caliper slide pins, rebuild or replace seized calipers and wind back the piston when fitting new pads. A sticking caliper makes the car pull to one side and the wheel run hot.
Examples
The front left brake caliper is sticking, so that wheel is much hotter than the others.
Use the scan tool to open the electric parking brake before you push back the caliper piston.
The depth of the grooves in a tire's tread, measured in millimeters. In many countries, including EU countries and Turkey, the legal minimum for car tires is 1.6 mm.
Where you use it
Technicians measure tread depth with a gauge at every service and record it on the inspection sheet. Small bars in the grooves (tread wear indicators) show when 1.6 mm is reached; many experts advise replacing tires earlier.
Examples
The front tires have a tread depth of only 2 mm, so we recommend replacing them before winter.
Uneven tread depth across the tire usually means a wheel alignment problem.
To remove trapped air from a hydraulic or cooling system, for example the brake lines, by letting fluid flow out through a bleed screw until no bubbles remain.
Where you use it
Most often heard as bleed the brakes. Air in the brake lines gives a soft or spongy pedal. Technicians bleed the brakes after replacing a caliper or hose and when changing the brake fluid, often with a pressure bleeder or a scan tool for the ABS unit.
Examples
The pedal still feels spongy, so bleed the brakes again, starting with the rear right wheel.
You must bleed the cooling system after changing the water pump.
The base frame of a vehicle together with the systems mounted on it, such as suspension, steering and brakes. In engineering it often means everything under the body that makes the car ride and handle.
Where you use it
Car makers have chassis engineers and chassis departments that work on ride, handling and braking. You also hear chassis number (another name for the VIN), chassis dyno and chassis tuning.
Examples
The chassis team spent two weeks tuning the suspension for European roads.
Please confirm the chassis number before you order the parts.
Usage note
Pronounced 'CHASS-ee' or 'SHASS-ee'; the final s is silent. The plural is spelled the same (chassis) but ends with a z sound.
Common phrases
chassis number · chassis engineer · chassis dyno · rolling chassis
The stage of car production at which the sheet metal parts of the body have been welded together, before painting and before the engine, trim and other parts are added.
Where you use it
Shortened to BIW. Used in body engineering and plant talk: BIW weight, BIW stiffness, BIW shop. Engineers try to reduce BIW weight with high-strength steel and aluminum while keeping crash performance.
Examples
The body-in-white weighs 285 kg, about 20 kg less than the previous model.
Each body-in-white is measured on the CMM before it goes to the paint shop.
A part of the vehicle body, usually at the front and rear, designed to fold in a controlled way during a collision so that it absorbs energy and protects the passenger cell.
Where you use it
Used in safety engineering, sales and bodywork. Engineers design crumple zones with crash boxes and load paths; body shop technicians follow the maker's repair methods, because a badly repaired crumple zone may not work in the next crash.
Examples
The front crumple zone absorbed most of the energy, and the cabin stayed intact.
Do not straighten the crash box; the crumple zone parts must be replaced.
Common phrases
front crumple zone · crash box · passenger cell · absorb crash energy
The part at the very front or rear of a car that protects the body in low-speed impacts. It usually has a plastic cover over a metal reinforcement beam.
Where you use it
Common in bodywork, sales and insurance. People talk about the front and rear bumper, bumper cover, bumper beam and parking sensors in the bumper. Body shops repair, paint or replace bumpers after minor accidents.
Examples
The rear bumper is cracked, and one parking sensor is hanging out.
Replacing the front bumper cover means the radar sensor must be recalibrated.
The front window of a vehicle, made of laminated safety glass. It also supports the roof structure and holds the camera used by many driver assistance systems.
Where you use it
Common in service and insurance. People repair a chip or replace a cracked windshield; after replacement the front camera usually needs calibration. Other words you hear are wipers, washer fluid and rain sensor.
Examples
A stone chip on the windshield has turned into a 20 cm crack.
After the windshield replacement, the lane keeping camera was recalibrated.
Usage note
Windshield is American English; British English says windscreen. The rear window is the rear window or back glass in both.
A fabric bag that inflates in milliseconds during a crash to cushion the occupants. Airbags work together with seat belts as part of the restraint system.
Where you use it
Airbags deploy (open); after a crash the deployed airbags, the control module and often the seat belt pretensioners are replaced. The system is often called SRS. Disconnect the battery and wait the time given in the manual before working on it.
Examples
Both front airbags deployed, so the airbag module must be replaced as well.
The airbag warning light stays on because of a faulty seat connector.
A construction in which the body and the frame are one welded structure that carries all the loads. Almost all modern passenger cars and crossovers are built this way.
Where you use it
Usually contrasted with body-on-frame, where a separate body sits on a ladder frame, as on many pickups and large off-roaders. Unibody is the common US term; in Europe engineers often say monocoque or self-supporting body.
Examples
A unibody is lighter and stiffer than a body-on-frame design.
Because it has a unibody, the SUV drives more like a car than a truck.
Common phrases
unibody construction · body-on-frame · ladder frame · monocoque
Short for electronic control unit (or engine control unit): a small computer that reads sensors and controls actuators, for example injection timing in an engine. Modern cars have dozens of them.
Where you use it
Technicians read, reset, flash (update the software in) and replace ECUs. Engineers talk about ECU software, calibration, inputs and outputs. Some units have their own names, such as ECM, TCM and BCM.
Examples
After replacing the ECU, we had to program it with the vehicle's VIN.
The engine ECU limits power when the coolant temperature gets too high.
Common phrases
flash the ECU · ECU software · replace the ECU · ECU update
A component that measures something, such as temperature, pressure, speed or position, and sends it as an electrical signal to a control unit.
Where you use it
A car has many sensors: the oxygen (lambda) sensor, crankshaft position sensor, wheel speed sensors and parking sensors. Technicians test, clean and replace sensors and check their readings with a scan tool.
Examples
The code points to a faulty oxygen sensor on bank one.
Check the wheel speed sensor wiring before you replace the ABS module.
The main in-vehicle network that lets control units share data over a pair of twisted wires (CAN High and CAN Low). CAN stands for Controller Area Network.
Where you use it
Used by electrical engineers and diagnostic technicians. People talk about CAN messages, CAN traffic and communication faults (U-codes). A quick check: with the battery disconnected, the resistance between CAN High and CAN Low is normally about 60 ohms.
Examples
Several modules lost communication, so we suspect a short on the CAN bus.
The gateway module connects the powertrain CAN bus to the body network.
Common phrases
CAN bus communication · CAN High · CAN Low · CAN message · U-code
A bundle of wires, connectors and terminals, wrapped and routed together, that carries power and signals between the electrical parts of a vehicle.
Where you use it
Technicians repair or replace a wiring harness after chafing, water ingress or rodent damage; engineers design harness routing and connector layouts. People also say loom, especially in British English.
Examples
A mouse chewed through the engine wiring harness, so several sensors are offline.
The wiring harness rubs against the bracket here; add a clip to keep it away.
Short for advanced driver assistance systems: features that use cameras, radar and other sensors to help the driver, such as automatic emergency braking, lane keeping and blind spot warning.
Where you use it
Used in product, engineering and service work. After a windshield replacement or wheel alignment, ADAS cameras and radars often need calibration. In the EU, new cars must now have several ADAS features, such as automatic emergency braking.
Examples
Book an ADAS calibration after the windshield is replaced.
The ADAS team is testing the emergency braking function at night with pedestrian targets.
The central screen and computer that combine navigation, audio, phone connection, vehicle settings and apps in one system.
Where you use it
Common in sales and service. Customers report frozen screens, Bluetooth problems or phone mirroring issues; technicians reset or update the infotainment system, often over the air (OTA). The hardware unit is called the head unit.
Examples
The infotainment system restarts by itself every few minutes.
Version 4.2 of the infotainment system adds wireless phone mirroring.
Common phrases
infotainment screen · infotainment update · head unit · over-the-air update
A component that turns an electrical command from a control unit into movement, for example a motor that opens the throttle, moves a valve or locks a door.
Where you use it
Sensors measure and actuators act. Technicians test actuators with a scan tool by commanding them on and off (actuator test). Examples are the EGR valve, turbo wastegate actuator, door lock actuators and fuel injectors.
Examples
Run the actuator test to see if the EGR valve opens and closes.
The wastegate actuator is stuck, so the turbo can't build full boost.
Common phrases
actuator test · door lock actuator · faulty actuator · electric actuator
A cruise control system that uses radar and often a camera to keep a set speed and automatically slow down or speed up to keep a safe distance from the vehicle ahead.
Where you use it
Shortened to ACC. Drivers set the speed and the following distance; stop-and-go versions can brake to a stop in traffic. Technicians calibrate the front radar after bumper repairs or alignment work.
Examples
Adaptive cruise control is not available because the radar sensor is blocked by snow.
Set the adaptive cruise control to 110 km/h and the longest following distance.
Common phrases
set the adaptive cruise control · following distance · stop-and-go function · radar sensor
A standard code stored by a control unit when it detects a fault, such as P0300. The first letter shows the system: P for powertrain, B for body, C for chassis and U for network.
Where you use it
Usually shortened to DTC or simply called a fault code. Technicians read, record and clear codes with a scan tool. A code tells you where to start looking, not which part to replace, so always confirm it with tests.
Short for On-Board Diagnostics, second generation: a standard self-diagnosis system with a 16-pin connector that lets any scan tool read emission-related fault codes and live data.
Where you use it
Required on cars sold in the US from model year 1996; the European version, EOBD, has been required on new petrol cars since 2001 and diesel cars since 2004. Technicians plug into the OBD port, usually under the dashboard.
Examples
Plug the scanner into the OBD-II port and switch the ignition on.
Generic OBD-II data shows the misfire, but you need the dealer tool to see the injector values.
To find the cause of a fault by checking the symptoms, reading data and testing parts step by step, before any repair is made.
Where you use it
A core verb in every workshop. You diagnose a fault, a noise or an electrical problem; the noun is diagnosis, and workshops charge a diagnostic fee. Technicians often just say diag.
Examples
It took us two hours to diagnose the intermittent electrical fault.
Don't replace any parts until you've diagnosed the problem properly.
Usage note
Turkish speakers often say 'make a diagnose'. Diagnose is the verb and diagnosis is the noun: make a diagnosis, or simply diagnose the fault.
Common phrases
diagnose a fault · diagnose the problem · hard to diagnose · misdiagnose
The distance or time between scheduled maintenance visits set by the manufacturer, for example every 15,000 km or once a year, whichever comes first.
Where you use it
Found in owner's manuals, service schedules and warranty terms. Some cars use fixed intervals; others use flexible intervals calculated by the car itself. Customers often ask whether they can extend or skip a service.
Examples
The service interval for this engine is 20,000 km or 12 months.
Going far beyond the service interval may affect the warranty.
Usage note
English uses a comma as the thousands separator (15,000 km) and a point for decimals, the opposite of Turkish (15.000 km; 2,5 litre).
Common phrases
service interval reminder · extended service interval · reset the service interval · fixed service interval
A handheld device or laptop software that connects to the vehicle's diagnostic port to read and clear fault codes, view live data and run tests on control units.
Where you use it
Also called a scanner or diagnostic tool. A generic OBD scanner reads basic engine data; a dealer-level or OEM scan tool can also code parts, update software and run bidirectional (actuator) tests.
Examples
Connect the scan tool and check the live data for fuel trims.
Our generic scan tool can't code the new battery, so we need the dealer software.
Common phrases
connect the scan tool · dealer scan tool · live data · bidirectional control
Draining the old engine oil and refilling with new oil of the correct grade, usually together with a new oil filter. It is the most basic routine service job.
Where you use it
Customers book an oil change; technicians do an oil and filter change and reset the service reminder. Oil grades are read aloud like 'five W thirty' (5W-30), and the manual lists the required oil specification.
Examples
The car is due for an oil change in 1,000 km.
We did an oil change with 0W-20 oil and reset the service light.
Common phrases
oil and filter change · due for an oil change · oil change interval · oil grade
The amber engine-shaped warning light on the dashboard that comes on when the engine or emission control system detects a fault and stores a code.
Where you use it
Customers say the check engine light is on or came on. The official name is MIL (malfunction indicator lamp). A steady light means a fault should be checked soon; a flashing light usually means a serious misfire that can damage the catalytic converter.
Examples
The check engine light came on yesterday, and the car feels down on power.
If the check engine light is flashing, slow down and have the car checked as soon as possible.
Common phrases
check engine light comes on · flashing check engine light · MIL · clear the light
A failure of the fuel and air in one or more cylinders to burn properly. The engine shakes, runs rough and loses power, and unburned fuel can overheat the catalytic converter.
Where you use it
Also a verb: the engine misfires, cylinder three is misfiring. Codes P0301 to P0308 point to a specific cylinder, and P0300 means random or multiple misfires. Common causes are spark plugs, ignition coils, injectors and low compression.
Examples
Swap the ignition coils between cylinders two and three to see if the misfire moves.
The engine misfires under load, especially when accelerating uphill.
Common phrases
engine misfire · random misfire · misfire under load · cylinder misfire
A protective mode in which a control unit limits engine power, speed or gear selection after detecting a serious fault, so the car can still be driven slowly to a workshop.
Where you use it
Also called limp-home mode or safe mode. Customers say the car went into limp mode and lost power; technicians read the codes to find what triggered it. Automatic transmissions often stay in one gear in limp mode.
Examples
The car went into limp mode on the highway and wouldn't go above 60 km/h.
A boost pressure fault is the most common reason for limp mode on this engine.
Usage note
Turkish drivers often say 'araç emniyete aldı'. In English say the car went into limp mode, not 'took safety'.
Common phrases
go into limp mode · limp-home mode · stuck in limp mode · reduced power
A wrench that lets you tighten a nut or bolt to an exact specified torque. The common click type gives a click when the set value is reached.
Where you use it
Used for wheel nuts, cylinder head bolts, suspension and brake parts. Technicians set the torque wrench to the spec in the manual. Torque wrenches need regular calibration and should not be used to loosen bolts.
Examples
Tighten the wheel nuts with a torque wrench, not with the impact gun.
Our torque wrenches are calibrated every six months.
Common phrases
click-type torque wrench · set the torque wrench · calibrate the torque wrench · torque spec
To lift a vehicle, or one side or corner of it, off the ground with a jack, for example to change a wheel or work underneath.
Where you use it
Common in workshops and owner's manuals: jack up the car, jack it up at the jacking points. Safety rule: never work under a car supported only by a jack; use jack stands (UK: axle stands) or a lift.
Examples
Jack up the front of the car and put it on stands before you remove the wheels.
Only jack up the vehicle at the marked points under the sills.
Common phrases
jack up the car · jacking point · jack stands · vehicle lift
A production line where a vehicle moves from station to station and workers or robots add parts in a fixed order until the car is complete.
Where you use it
Common in plant talk: a car rolls off the assembly line; the line stops, restarts or runs at a set cycle time. The main areas of a car plant are the body shop, the paint shop and final assembly.
Examples
The first pre-series cars came off the assembly line in March.
A missing part stopped the assembly line for twenty minutes.
Common phrases
roll off the assembly line · stop the line · final assembly · assembly line worker
Short for original equipment manufacturer. In the car industry it usually means the vehicle maker itself; in the parts trade, OEM parts are the original parts made by or for that maker.
Where you use it
Engineers and suppliers say 'the OEM' for the carmaker they deliver to: OEM requirements, OEM approval, OEM plants. In service, people compare OEM or genuine parts with aftermarket parts.
Examples
The OEM wants the new samples by the end of the month.
For warranty repairs we may only use OEM parts.
Usage note
Turkish industry says ana sanayi for vehicle makers (OEMs) and yan sanayi for suppliers. Note that a supplier is not called an OEM in English, even if it makes original parts.
A company that supplies parts or complete systems directly to a vehicle maker. Tier 2 suppliers sell to Tier 1 companies, and Tier 3 suppliers usually provide raw materials or basic parts.
Where you use it
Common in purchasing, quality and project meetings. People say Tier 1 and Tier 2 as nouns: our Tier 1, a Tier 2 casting supplier. Tier 1 suppliers often develop whole systems such as seats, brakes or infotainment.
Examples
Our Tier 1 supplier delivers complete front-end modules to the line every two hours.
The defect started at a Tier 2 company, but the Tier 1 supplier is responsible to the OEM.
A controlled test in which a vehicle with instrumented dummies is crashed into a barrier, a pole or another vehicle to measure how well it protects people.
Where you use it
Used in safety engineering and in marketing. Cars are tested for regulations and by rating programs such as Euro NCAP, which gives up to five stars. Common types are frontal offset, side impact and pole tests.
Examples
The new SUV scored five stars in the Euro NCAP crash test.
The crash test data show high loads on the driver's chest.
Common phrases
crash test dummy · frontal crash test · side impact test · crash test rating
The area of a car plant, or a repair workshop, where bodies are cleaned, coated against corrosion and painted. In a plant the main layers are e-coat, primer, base coat and clear coat.
Where you use it
In a plant, the paint shop sits between the body shop and final assembly and is often the bottleneck. Quality staff look for paint defects such as dirt, runs and orange peel. In repair work, people say body and paint shop.
Examples
The paint shop is running at full capacity, so the extra shift starts on Monday.
Paint shop audits found dust inclusions on the roof of three bodies.
Common phrases
e-coat · base coat · clear coat · paint defect · body and paint shop
Short for Production Part Approval Process: the formal package of evidence a supplier submits to show that its production process can make parts that meet all customer requirements.
Where you use it
Used by supplier quality engineers. A PPAP includes items such as dimensional results, the control plan, the process FMEA and capability studies, plus a Part Submission Warrant (PSW). Parts may not be shipped for series production until the PPAP is approved.
Examples
We need to resubmit the PPAP because the material supplier has changed.
The PPAP was rejected because the capability study used too few parts.
Common phrases
submit the PPAP · PPAP approval · PPAP level 3 · Part Submission Warrant
The official approval showing that a vehicle type or component meets the legal technical and safety requirements of a market, so it can be sold and registered there.
Where you use it
Used in engineering, regulatory and export work. Engineers prepare homologation tests and documents for type approval; any change to lights, emissions or safety parts may need re-homologation for each market.
Examples
Homologation for the Gulf markets will take another three months.
The new headlamp design needs separate homologation before it can be used.
Common phrases
type approval · homologation tests · homologation documents · re-homologation
Tests that check whether a vehicle or part keeps working over its expected life, done on rough test tracks, on test rigs or with high-mileage test fleets.
Where you use it
Used in validation and quality engineering. Engineers plan accelerated durability tests that compress years of use into weeks, then tear down and inspect the parts. Results go into test reports and design reviews.
Examples
The rear subframe cracked after 60 percent of the durability testing program.
Durability testing on the rough-road track runs 24 hours a day with three driver shifts.
Common phrases
accelerated durability test · durability test track · test rig · durability fleet
A welding method in which two electrodes press sheets of metal together and pass a strong current through them, melting a small spot that joins the sheets. A car body has thousands of spot welds.
Where you use it
Used in the body shop, where robots do most spot welding. Quality teams check weld quality with ultrasonic tests and destructive chisel or peel tests. In repair work, body shops drill out spot welds to replace panels.
Examples
Robots do about 4,500 spot welds on each body in the welding shop.
The peel test showed poor spot welding on the B-pillar: several welds were too small.
An official action in which a manufacturer asks owners to bring vehicles back to a dealer so that a safety or compliance defect can be fixed free of charge.
Where you use it
Used by manufacturers, authorities and dealers. A manufacturer issues or announces a recall, the dealer checks for open recalls by VIN, and the work is done under a campaign code. It is also a verb: recall 50,000 vehicles.
Examples
Please check the VIN for open recalls before the car goes back to the customer.
The company recalled 12,000 vehicles to replace a faulty fuel pump.
Usage note
A recall is not the same as a service campaign or a technical service bulletin (TSB), which deal with non-safety issues and are often applied only when the car comes in for other work.
Common phrases
issue a recall · safety recall · open recall · recall campaign
The manufacturer's promise to repair or replace faulty parts free of charge for a set time or distance, for example three years or 100,000 km.
Where you use it
Central to dealer and after-sales work. A repair is under warranty or out of warranty; dealers submit warranty claims to the manufacturer, which approves or rejects them. An extended warranty is extra cover the customer pays for.
Examples
The car is still under warranty, so the gearbox repair is free.
The warranty claim was rejected because the service history was incomplete.
Usage note
Warranty and guarantee are close in meaning, but car makers and dealers normally say warranty. Instead of 'the car is in guarantee', say it is under warranty.
Common phrases
under warranty · warranty claim · extended warranty · void the warranty · warranty period
A business authorized by a manufacturer to sell its new vehicles under the brand's name, usually together with used cars, parts and servicing.
Where you use it
The owner is a dealer, and all of a brand's dealers form its dealer network. Departments include sales, service, parts and finance. Dealer is also used for the business itself: take it to the dealer.
Examples
Our dealership sold 140 new cars last month and serviced more than 900.
This software update can only be done at an authorized dealership.
Common phrases
authorized dealership · car dealership · dealership service department · dealer network
The workshop document that records the customer's concern, the vehicle details, the work authorized and, at the end, the cause, the repair, the parts and the labor charged.
Where you use it
Often shortened to RO. The service advisor opens the repair order, the technician writes the story (concern, cause, correction), and the RO is closed and invoiced. Warranty claims are checked against what is written on it.
Examples
Please write the exact customer complaint on the repair order, not just 'check car'.
The repair order was closed before the road test was done.
Usage note
Many British workshops say job card for the same document. Turkish 'iş emri' covers both.
Common phrases
open a repair order · close the repair order · RO number · customer concern
The time allowed or charged for a repair job. Manufacturers publish standard labor times that dealers use for customer quotes and warranty claims.
Where you use it
Common in service departments. Labor time is multiplied by the labor rate per hour to get the labor cost; flat-rate time is paid by the book, not by the actual hours. British English spells it labour.
Examples
The standard labor time for a clutch replacement on this model is 4.8 hours.
The quote includes parts, labor time and an ADAS calibration.
Common phrases
standard labor time · labor rate · labor cost · flat-rate time
The market for parts, accessories and services that are not supplied by the vehicle maker, such as non-original spare parts, independent workshops and tuning products.
Where you use it
Often used as an adjective: aftermarket parts, aftermarket wheels, aftermarket alarm. Dealers compare aftermarket parts with OEM or genuine parts, and aftermarket modifications can affect warranty claims.
Examples
The electrical fault was caused by an aftermarket alarm that was badly installed.
Aftermarket brake pads are cheaper, but check that they meet ECE R90.
Usage note
Turkish 'yan sanayi' means two things: the supplier industry (in English, suppliers or Tier 1 and Tier 2) and non-original spare parts (aftermarket parts). Choose the English word by context.
One of the versions of a model, each with a set package of equipment and price, for example a basic, a mid-range and a top version with leather seats and larger wheels.
Where you use it
Used in sales, marketing and production planning. Customers compare trim levels; salespeople explain what each trim includes and which options can be added. People often just say trim: the top trim, the base trim.
Examples
The mid trim level already has a reversing camera and adaptive cruise control.
Most of our customers choose the second trim level because of the price.
Common phrases
top trim · base trim · trim level comparison · optional extras
A short drive that a potential buyer takes in a car before deciding to buy it, usually with a salesperson and on a route chosen by the dealer.
Where you use it
Customers book or take a test drive; dealers keep demo cars for test drives and check the driving license first. It is also a verb: test-drive a car. Electric car test drives are often longer so customers can try charging.
Examples
Would you like to book a test drive for Saturday morning?
After the test drive, the customer asked about the hybrid version.
Usage note
Technicians call the drive after a repair a road test, not a test drive. Test drive is for buyers.
Common phrases
book a test drive · take a test drive · test drive car · test-drive a car
A used car that a customer gives to the dealer as part of the payment for a new or newer car. Its agreed value is taken off the price.
Where you use it
Used in sales. The dealer appraises the trade-in and makes a trade-in offer; the customer may trade in the old car (phrasal verb, two words). The trade-in value depends on age, mileage, condition and service history.
Examples
We can offer you 650,000 lira for your trade-in.
She wants to trade in her diesel car for a plug-in hybrid.
Common phrases
trade-in value · trade-in offer · trade in a car · appraise the trade-in
Short for vehicle identification number: a unique 17-character code for each vehicle that shows the maker, model details and serial number. The letters I, O and Q are not used.
Where you use it
Used everywhere in after-sales: ordering parts, checking recalls, warranty claims, registration and insurance. You find it on the registration document, on a plate visible through the windshield and stamped on the body. People say 'VIN' as one word, or 'VIN number'.
Examples
Can you send me a photo of the VIN plate so I can order the right parts?
The VIN on the registration document doesn't match the one on the car.
Usage note
In Turkey the VIN is usually called şasi numarası. In English 'chassis number' is also understood, but VIN is the standard term.
Common phrases
VIN plate · VIN check · decode the VIN · VIN number
The person at a dealership or workshop who receives customers, writes up their concerns, explains the work and costs, and keeps them updated until the car is ready.
Where you use it
The service advisor is the link between the customer and the technicians: they open the repair order, get approval for extra work and handle the vehicle handover. In some companies the title is service consultant or service receptionist.
Examples
Your service advisor will call you once the technician has diagnosed the noise.
The service advisor walked around the car with the customer and noted the scratches.
Common phrases
speak to your service advisor · vehicle handover · walk-around check · customer approval
The checks a dealer carries out on a new car before handing it to the customer, such as removing transport protection, checking fluids and tire pressures and installing software updates.
Where you use it
Usually shortened to PDI. The workshop does the PDI from the manufacturer's checklist, and the car is washed and prepared for handover. Problems found at PDI are often claimed under warranty or as transport damage.
Examples
The pre-delivery inspection found a paint scratch on the tailgate.
Please finish the pre-delivery inspection by Thursday; the customer is collecting the car on Friday.
Common phrases
PDI checklist · carry out the PDI · vehicle handover · transport damage
Ten questions from this glossary. Pick the right meaning for each term and see your score.
How to learn automotive vocabulary
Read real texts from the field: workshop manuals, technical service bulletins, scan tool menus, supplier datasheets and recall notices all use this vocabulary in its natural context.
Learn each part together with the verbs mechanics really use: replace the brake pads, bleed the brakes, clear a fault code, torque the bolts to spec.
Watch out for US and UK differences: tire/tyre, hood/bonnet, trunk/boot, windshield/windscreen, gas/petrol. Manuals from American and European brands may use different words for the same part.
Many Turkish workshop words come from French (debriyaj, şanzıman, rölanti, buji), so the English word often looks nothing like the Turkish one. Keep a list of these pairs and review it often.
Practice describing a fault in three short sentences: the symptom, when it happens and what you have already checked. This is exactly what a repair order, a warranty claim or a message to technical support needs.
Frequently asked questions
How can I learn English for the automotive industry?
Read real texts from the field and notice how the words are used: workshop manuals, service bulletins, scan tool screens, supplier specifications and test reports. Learn each term with its usual partners (read a fault code, replace the clutch kit, under warranty) and use new words right away in your own reports, emails and conversations with colleagues.
Which automotive terms should I learn first?
Start with the main systems and the words you hear every day in a workshop or plant: engine, transmission, brakes, suspension, steering, tires, ECU, sensor, fault code, warranty and recall. Then move on to electric vehicle and battery terms, electronics, manufacturing and quality. The terms in this glossary follow the same order, from most to least essential.
What is the difference between engine and motor in English?
In automotive English, engine normally means an internal combustion engine that burns petrol or diesel, while motor means an electric motor. So a hybrid car has an engine and an electric motor. In everyday American speech motor can also mean a car engine (motor oil, motor vehicle), but 'electric engine' sounds wrong to most engineers.
Why do American and British car manuals use different words?
The two varieties of English developed their own car vocabulary. Americans say hood, trunk, windshield, gas and transmission; British speakers say bonnet, boot, windscreen, petrol and gearbox. Global manufacturers usually pick one style for their documents, so learn to recognize both and stay consistent in your own writing.
