How we test cars

Test lab

Tested by us, rated by you

Our road testers scrutinise around 140 cars every year, subjecting each one to more than 1,200 miles of road testing and hours of evaluations in the laboratory. Their observations are used to compile the report and calculate the Which? verdict for each car.

However, a great car must do much more than excel in our road tests. It needs to impress real owners, too. The results of the annual Which? Car Survey reveal exactly what you think of your cars. Your responses help produce unique reliability and owner satisfaction ratings that sit alongside the Which? verdict, giving you a comprehensive guide to each model. 

We prioritise testing mainstream cars because that's what most of you buy. However, we do cover the full market, from superminis to sports cars, and we tailor our ratings to the requirements of each class. We also have more than 100 car video reviews online.

Take out a £1 trial subscription to Which? and find out which Best Buy cars we recommend, and the Don't Buy cars you should avoid.

How we test cars video

 

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Testing cars on the road

We attend launches for all the cars that are most important to UK consumers. We also borrow press fleet cars for prolonged periods of time as soon as they become available. Our findings go into our First Drive report, which contains an initial verdict on the car.

2011 Mini swerve test

Each car we road test is driven on all types of road, including unclassified roads (e.g. country lanes), B roads, A roads, motorways and town/city routes. We assess everything from the ride comfort to the built-in sat nav and in-car entertainment systems. 

Testing cars in the lab

After we’ve had hands-on experience with a car, we send it to our lab – the biggest car-testing facility in Europe. There, we simulate the real conditions of driving on our rolling road. Large industrial fans replicate wind resistance, and throughout the test we assess performance, fuel economy and emissions.

We also measure braking, noise, interior space, all-round visibility and heating performance - the latter in a special climate chamber that keeps the outside temperature at -10°C.

Outside on the test track, we conduct an avoidance test, swerving around cones placed in the exact same position every time. The assessment also evaluates the stability control (ESC) intervention to stabilise the car.

Which? avoidance test video

 

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