11 / Glossary
Car talk,
decoded.
65 words and acronyms you will hear from instructors, mechanics, salespeople and insurers.
- AABS
- Anti-lock Braking System. Pulses the brakes so the wheels don't lock, letting you steer during an emergency stop.
- AADAS
- Advanced Driver Assistance Systems: lane keeping, automatic emergency braking, adaptive cruise control and similar.
- AADI
- Approved Driving Instructor, registered with the DVSA. Look for the green (qualified) or pink (trainee) badge in the windscreen.
- AAlternator
- A generator driven by the engine that charges the 12V battery and powers the electrics.
- AAWD / 4WD / 4x4
- All four wheels are driven. 4x4 usually means a tougher off-road system.
- BBanger
- British slang for an old, cheap and slightly unreliable car.
- bbhp / PS / kW
- Units of power. 1 PS ≈ 0.986 bhp, 1 kW ≈ 1.34 bhp.
- BBite point
- In a manual car, the point where the clutch starts to connect the engine to the wheels and the car begins to move.
- BBlack box
- A telematics insurance policy. A small device or app scores your driving, and careful drivers pay less.
- BBlind spot
- Areas around the car your mirrors don't show. Check over your shoulder before moving off or changing lanes.
- BBonnet / boot
- British for hood and trunk.
- CCamber / Toe / Caster
- Wheel alignment angles: camber is vertical tilt, toe is whether the tyres point slightly inwards or outwards, and caster is steering-axis tilt that makes the wheel self-centre.
- CCamshaft
- A spinning shaft with lobes that opens and closes the engine's valves at the right moment.
- CCat N / Cat S
- Insurance write-off categories. Cat N is non-structural damage, Cat S is structural. Both can be repaired and driven again but are worth less.
- CCatalytic converter
- Part of the exhaust that turns toxic gases into less harmful ones.
- ccc
- Cubic centimetres of engine size. 1,598 cc ≈ 1.6 litres.
- CChassis
- The underpinnings of a car: frame, suspension, steering and brakes.
- CClutch
- Connects and disconnects the engine from the gearbox so you can change gear and stop without stalling.
- CCoasting
- Rolling with the clutch down or in neutral. It reduces control and is marked as a fault on the test.
- CCrumple zone
- Parts of the car designed to collapse in a crash and absorb energy.
- CCVT
- Continuously Variable Transmission. An automatic with no fixed gears, common in Toyota hybrids.
- DDifferential
- Gears that let the left and right wheels turn at different speeds through a corner.
- DDPF
- Diesel Particulate Filter. Traps soot and needs regular longer, faster drives to clean itself.
- DDual carriageway
- A road with a central reservation separating traffic in each direction.
- DDVLA
- Driver and Vehicle Licensing Agency. Handles licences, car tax and registrations.
- DDVSA
- Driver and Vehicle Standards Agency. Runs driving tests and the MOT scheme.
- EECU
- Engine Control Unit, the computer that runs the engine.
- EESC / ESP
- Electronic Stability Control. Brakes individual wheels to stop a skid.
- EEuro NCAP
- Independent crash-testing programme that rates cars from 0 to 5 stars.
- FFWD
- Front-wheel drive.
- HHard shoulder
- The emergency lane on the far left of many motorways. Only for breakdowns and emergencies.
- HHazard perception
- Part of the theory test where you click when you see developing hazards in video clips.
- HHot hatch
- A high-performance version of a small hatchback, like the VW Golf GTI or Honda Civic Type R.
- HHybrid (HEV / MHEV / PHEV)
- A car with both an engine and an electric motor. Full, mild and plug-in versions differ in battery size.
- IInsurance group
- A rating from 1 (cheapest) to 50 that insurers use to price cover.
- kkWh
- Kilowatt-hour, a unit of energy. EV battery size and charging cost are measured in kWh.
- LLay-by
- A small parking area at the side of a road for short stops.
- MMonocoque
- A car body that is also its structural frame. Almost every modern car is built this way.
- MMOT
- Annual roadworthiness test for cars over 3 years old. Named after the old Ministry of Transport.
- MMotor
- Informal British word for a car ("nice motor").
- mmpg
- Miles per gallon. A UK gallon is 4.546 litres.
- NNo-claims bonus
- A discount on your insurance that grows each year you don't make a claim.
- OOversteer / understeer
- Oversteer: the rear slides out. Understeer: the front won't turn as much as you asked and runs wide.
- PP plates
- Optional green plates showing you have recently passed.
- PPass Plus
- An optional extra course after you pass, covering motorways, night and bad weather. Some insurers give a discount.
- PPCP
- Personal Contract Purchase, a finance deal with low monthly payments and a large final payment.
- PPetrolhead
- Someone who loves cars.
- RRed route
- A road, mainly in London, where you can't stop at all on red lines.
- RRegen
- Regenerative braking. EVs and hybrids recover energy when slowing down.
- rrpm
- Revolutions per minute, how fast the engine is spinning. Shown on the rev counter.
- SShow me, tell me
- Vehicle safety questions asked during the practical driving test.
- SSmart motorway
- A motorway that uses technology such as variable speed limits and lane closures to manage traffic.
- SSORN
- Statutory Off Road Notification. Tells DVLA a car is off the road so it does not need tax.
- SSupercharger
- Like a turbo but driven by a belt from the engine. Also Tesla's name for its rapid chargers.
- TTorque
- Twisting force, measured in Nm or lb-ft. It is what you feel pushing you forward.
- TTraction control
- Cuts power when a driven wheel starts to spin on a slippery surface.
- TTurbo
- A turbine powered by exhaust gas that forces more air into the engine for more power.
- UULEZ / CAZ
- Ultra Low Emission Zone (London) and Clean Air Zones (other cities). Older, dirtier cars pay a daily charge.
- VV5C
- The vehicle logbook showing the registered keeper. It is not proof of ownership.
- VVED
- Vehicle Excise Duty, also called car tax or road tax.
- VVIN
- Vehicle Identification Number, the car's unique 17-character fingerprint.
- WWheelbase
- Distance between the centres of the front and rear wheels.
- WWLTP
- The official test used to measure fuel economy, emissions and EV range.
- WWrite-off
- A car the insurer decides isn't worth repairing after a crash or theft.
- ZZebra crossing
- A black and white striped pedestrian crossing with flashing orange beacons.