Car jargon buster

0–9

4x4 (Four-wheel drive)

Power goes to all four wheels for grip off road or in snow. Usually uses a little more fuel than two-wheel drive. Engine and gearbox.

A

Adaptive cruise (Adaptive cruise control)

Cruise control that keeps a set gap to the car in front, slowing down and speeding up for you. Kit and condition.

AdBlue (Diesel exhaust fluid)

A fluid many modern diesels use to cut nitrogen oxide emissions. It has its own tank and must be topped up; many cars will not restart if it runs out. Engine and gearbox.

APR (Annual percentage rate)

The yearly cost of borrowing, including interest and compulsory fees. Use it to compare finance offers. Price and buying.

AWD (All-wheel drive)

All-wheel drive sends power to all four wheels when needed. Badges and trim names.

B

BHP (Brake horsepower)

Engine power. PS (metric horsepower) is almost the same: 100 PS is about 99 bhp. One kilowatt (kW) is about 1.34 bhp. Engine and gearbox.

BlueHDi (Peugeot and Citroën diesel)

Peugeot and Citroën’s low-emissions diesel engine name. Badges and trim names.

C

Cambelt (Timing belt)

A toothed rubber belt that keeps the engine’s valves and pistons in step. It must be changed at the age or mileage the maker sets; if it snaps the engine can be badly damaged. Ask for the receipt. Engine and gearbox.

Cat C and Cat D (Older write-off categories)

Write-off categories used before October 2017. Cat C meant repairs cost more than the car was worth; Cat D meant they cost less. Cat S and Cat N replaced them, judged on damage instead of cost. History and paperwork. Source: ABI Code of Practice for the Categorisation of Motorised Vehicle Salvage (May 2025).

Cat N (Category N write-off)

An insurer wrote the car off after damage that did not affect its structure, such as cosmetic, electrical or mechanical damage. It can be repaired and used again. Ask what was damaged and how it was fixed. History and paperwork. Source: ABI Code of Practice for the Categorisation of Motorised Vehicle Salvage (May 2025).

Cat S (Category S write-off)

An insurer wrote the car off after damage to its structure (frame or chassis). It can be repaired and used again. Ask who repaired it, see the evidence, and expect insurance to ask about it. History and paperwork. Source: ABI Code of Practice for the Categorisation of Motorised Vehicle Salvage (May 2025).

CAZ (Clean Air Zone)

A city zone where vehicles that miss an emission standard pay to drive in. Only some zones charge private cars. Check a car’s reg on GOV.UK’s free vehicle checker. History and paperwork. Source: GOV.UK: driving in a Clean Air Zone.

Climate control

Air conditioning that holds a temperature you set. Dual-zone lets the driver and front passenger choose their own. Kit and condition.

CVT (Continuously variable transmission)

An automatic with no fixed gears, common on hybrids and small cars. It feels smooth but can sound busy when you accelerate hard. Engine and gearbox.

D

dCi (Renault and Nissan diesel)

The diesel engine name used by Renault, Dacia and Nissan. Badges and trim names.

Digital service history

Many makers now record services online instead of stamping a book. A dealer for that make can usually print the record for you. History and paperwork.

DMF (Dual-mass flywheel)

A two-part flywheel, common on diesels and manual cars, that smooths out vibration. It wears with the clutch and is often replaced at the same time. Engine and gearbox.

DPF (Diesel particulate filter)

Traps soot from a diesel’s exhaust and burns it off on longer, faster runs. Lots of short trips can block it, which can be costly. Ask how the car has been used. Engine and gearbox. Source: The AA: diesel particulate filters.

DSG (Dual-clutch gearbox)

An automatic gearbox with two clutches for quick, smooth changes. Volkswagen group cars call it DSG. Ask whether its oil has been changed on schedule. Engine and gearbox.

E

EcoBoost (Ford petrol)

Ford’s name for its turbocharged petrol engines. Badges and trim names.

EGR (Exhaust gas recirculation)

A valve that feeds some exhaust back into the engine to cut emissions. It can clog with soot, bringing on a warning light or rough running. Engine and gearbox.

Euro 6 (Emission standard)

The European exhaust emission standard the car was built to. For cars, Clean Air Zones usually ask for at least Euro 6 diesel or Euro 4 petrol. History and paperwork. Source: GOV.UK: driving in a Clean Air Zone.

EV (Electric vehicle)

Runs only on a battery you charge. Ask about the battery’s health, which charging cables come with it and the range it really gets. Hybrid and electric.

Ex-demo (Ex-demonstrator)

A car a dealer used for test drives and display. Usually low mileage, with the dealer as the only former keeper. Price and buying.

Ex-fleet (Ex-lease or ex-company)

The car was run by a business, a lease company or a hire firm. Often serviced on time, sometimes with high mileage. Price and buying.

F

FDSH (Full dealer service history)

Every service was done by a main dealer for that make (FMDSH: full main dealer service history). Ask to see the record and check the gaps between services. History and paperwork.

Former keepers (Registered keeper history)

How many people have been the registered keeper. “One owner from new” is seller wording that usually refers to one keeper since first registration, but keeper and legal owner are not always the same. The V5C shows the number of former keepers. History and paperwork. Source: GOV.UK: vehicle log book (V5C).

FSH (Full service history)

The seller says the car has been serviced every time the maker recommends. Ask to see the stamps, invoices or digital record, and check the dates and mileages. History and paperwork.

H

Head gasket

The seal between the engine block and cylinder head. Failure can cause overheating, white exhaust smoke or coolant loss, and it is an expensive repair. Engine and gearbox.

HP (Hire purchase)

A deposit, then fixed monthly payments. You own the car after the last payment; until then the finance company does. Price and buying.

HPI clear (Vehicle history check)

The seller says a paid history check (HPI is one provider) found no outstanding finance, insurance write-off or stolen record. C4R has not checked this, so consider running your own. History and paperwork. Source: GOV.UK: checks when buying a used car.

I

Import (Grey import)

A car built for another country and brought into the UK outside the maker’s UK network. Parts, insurance and resale can differ. Ask for the import paperwork. Price and buying.

Insurance write-off

An insurer decided the car was not worth repairing, or not safe to repair. The category says how bad it was: A and B never return to the road; S and N can be repaired. History and paperwork. Source: ABI Code of Practice for the Categorisation of Motorised Vehicle Salvage (May 2025).

ISOFIX (Child seat mounts)

Standard mounting points for child seats, built into the rear seats and sometimes the front passenger seat. Kit and condition.

K

Kerbed (Kerbed alloys)

Scuffs on the alloy wheel rims from touching kerbs. Usually cosmetic, but deep damage can affect how the tyre seals. Kit and condition.

L

Long MOT (12 months MOT)

The car comes with most of a year before its next MOT is due. Check the actual expiry date free on GOV.UK. History and paperwork. Source: GOV.UK: check MOT history.

M

Mild hybrid (MHEV)

A small electric system that helps the engine and saves some fuel. It cannot drive the car on electric power alone. Hybrid and electric.

MOT (Annual roadworthiness test)

The yearly safety and emissions test cars need from three years old in Great Britain (four in Northern Ireland). Check any car’s MOT history, mileages and advisories free on GOV.UK. History and paperwork. Source: GOV.UK: getting an MOT, GOV.UK: check MOT history.

MOT advisory

Something the MOT tester noted that did not fail the test but may need work soon, such as tyres wearing or light corrosion. Advisories are listed in the free GOV.UK MOT history. History and paperwork. Source: GOV.UK: check MOT history.

N

NAV (Satellite navigation)

Built-in satellite navigation. Badges and trim names.

O

OIRO (Offers in the region of)

The price is a guide and the seller is open to offers around it. Price and buying.

ONO (Or nearest offer)

The seller will consider offers close to the asking price. OVNO (or very near offer) means they expect only a small reduction. Price and buying.

Outstanding finance

Money still owed on the car under a finance agreement. Until it is paid off the finance company owns the car, so a history check should show none before you pay. Price and buying. Source: GOV.UK: checks when buying a used car.

P

Panoramic roof

A large glass roof, sometimes opening, that lets more light into the cabin. Kit and condition.

PCP (Personal contract purchase)

Lower monthly payments with a large optional final payment (the balloon) to keep the car. At the end you can pay it, hand the car back or part-exchange it. Price and buying.

PDC (Park distance control)

Parking sensors that beep faster as you get closer to an obstacle. Kit and condition.

PHEV (Plug-in hybrid)

A bigger battery you charge from a socket gives a short electric-only range, then the engine takes over. Cheapest to run when you charge it often. Hybrid and electric.

Phone mirroring (Apple CarPlay or Android Auto)

Shows your phone’s maps, music and messages on the car’s screen. Kit and condition.

Plus VAT (VAT qualifying)

“Plus VAT” means VAT is added to the price shown. “VAT qualifying” means a VAT-registered business buyer may be able to reclaim the VAT. Price and buying.

Pre-reg (Pre-registered)

A new car registered by a dealer, often to meet sales targets, then sold with very few miles. It counts as used, with one former keeper. Price and buying.

Private plate (Personalised registration)

A personalised registration number. Ask whether it stays with the car. If the seller is keeping it, they must take it off before the sale and the car gets another reg. History and paperwork. Source: GOV.UK: personalised registrations.

PSH (Part service history)

Some services are recorded, but not all. Ask which ones are missing and whether any work was done without paperwork. History and paperwork.

PX (Part exchange)

You trade in your current car and its value comes off the price. “PX welcome” means the seller will consider it. Price and buying.

PX to clear (Part exchange to clear)

A car a dealer took in part exchange and wants to sell quickly, often priced low and offered with fewer checks than usual. Ask what has and has not been checked. Price and buying.

Q

quattro (Audi all-wheel drive)

Audi’s name for its all-wheel-drive system. Badges and trim names.

R

R-Design (Volvo trim)

Volvo’s sport-styled trim level. Badges and trim names.

Recon (Reconditioned)

Rebuilt or refurbished to working order rather than replaced with a new part. Ask who did the work and whether it came with a guarantee. Engine and gearbox.

Regen braking (Regenerative braking)

When you slow down, the motor works as a generator and puts energy back into the battery. It also means the brake pads usually last longer. Hybrid and electric.

Remap (Engine remap)

The engine’s software has been changed for more power or economy. It is a modification your insurer must be told about. Ask who did it and when. Engine and gearbox.

Run-flat tyres

Tyres that can be driven on for a limited distance at reduced speed after a puncture, so the car may carry no spare wheel. Kit and condition.

S

Self-charging hybrid (HEV)

A petrol engine plus an electric motor and a small battery the car charges itself. You never plug it in. Hybrid and electric.

SOH (Battery state of health)

How much of its original capacity an electric car’s battery still holds, as a percentage. Ask the seller for a recent battery health report. Hybrid and electric.

Sold as seen

Wording meaning the seller will not take the car back if faults appear. When the seller is a trader, it does not remove the buyer’s legal rights. In a private sale, the car must still match its description. Price and buying. Source: Which?: your rights if a car you bought has a problem, Consumer Rights Act 2015.

SORN (Statutory Off Road Notification)

The car is declared off the road to the DVLA. It must not be used on a public road until it is taxed again, except to drive to or from a pre-booked MOT or other testing appointment. History and paperwork. Source: GOV.UK: SORN (Statutory Off Road Notification).

Spares or repairs (Non-runner)

Sold with known faults, possibly not running at all. Expect to repair it or use it for parts, and to arrange transport. Price and buying.

S/S (Stop/start)

Stop/start switches the engine off while stationary to save fuel. Badges and trim names.

T

TDCi (Ford diesel)

Ford’s turbo-diesel engine name. Badges and trim names.

TDI (Volkswagen group diesel)

The turbo-diesel engine name used by Volkswagen, Audi, SEAT and Skoda. Badges and trim names.

Timing chain

A metal chain doing the cambelt’s job. Most are meant to last the life of the engine, but some wear early. A rattle on a cold start is worth asking about. Engine and gearbox.

Tow bar

A fitting for towing a trailer or caravan or carrying a bike rack. Check the car’s towing limit in the handbook. Kit and condition.

Trade sale (Trade only)

Offered to motor traders rather than the public. Sales between businesses do not carry the consumer rights of a normal retail sale. Price and buying. Source: Consumer Rights Act 2015.

Tread depth

How much grip is left on a tyre. The legal minimum for cars is 1.6mm across the central three-quarters of the tread, all the way round. Kit and condition. Source: The Highway Code, annex 6: vehicle maintenance.

TSI (Volkswagen group petrol)

The turbocharged petrol engine name used by Volkswagen, SEAT and Skoda; Audi calls its version TFSI. Badges and trim names.

Turbo (Turbocharger)

Uses exhaust gas to push more air into the engine for more power. On a test drive, listen for whining or whistling and watch for blue smoke. Engine and gearbox.

U

ULEZ (Ultra Low Emission Zone)

London’s zone covering every borough. Cars that miss its emission standards pay a daily charge to drive in it. “ULEZ compliant” is the seller’s word; check the reg on TfL’s free checker. History and paperwork. Source: TfL: Ultra Low Emission Zone.

V

V5C (Logbook)

The vehicle registration certificate from the DVLA. It names the registered keeper, who is not always the legal owner. For a private sale, check the keeper details match the seller; for any sale, check the VIN and colour match the car. History and paperwork. Source: GOV.UK: vehicle log book (V5C).

VED (Road tax)

Vehicle Excise Duty, usually called road tax or car tax. Tax does not pass to you when you buy a car: you must tax it yourself before you drive it away. History and paperwork. Source: GOV.UK: vehicle tax rates, GOV.UK: tell DVLA you have bought a vehicle.

VIN (Vehicle identification number)

The car’s unique 17-character serial number. It is on the V5C and on the car itself, often at the bottom of the windscreen. They must match. History and paperwork. Source: GOV.UK: vehicle log book (V5C), GOV.UK: checks when buying a used car.

W

Warranty

A promise to pay for some repairs for a set time. Read what it covers, the claim limit and who provides it. From a trader, it comes on top of your legal rights, not instead of them. Price and buying. Source: Which?: your rights if a car you bought has a problem.

X

xDrive (BMW all-wheel drive)

BMW’s name for its all-wheel-drive system. Badges and trim names.

Buying from a trader or privately

From a trader

From a trader (a dealer, or anyone selling cars as a business), the Consumer Rights Act 2015 says the car must be of satisfactory quality, fit for purpose and as described. Wording such as “sold as seen” does not remove those rights.

From a private seller

From a private seller, the car must be as described and the seller must have the right to sell it. There is no legal requirement for it to be of satisfactory quality, so checks before you buy matter more.

It is against the law for a trader to pose as a private seller. This is general information, not legal advice. Source: Consumer Rights Act 2015, Which?: your rights if a car you bought has a problem, GOV.UK: checks when buying a used car.