Which? car survey

The 2026 Which? car survey is now open. This is your chance to tell us about your car and how reliable it is.

Every year, tens of thousands of people complete the Which? car survey. The feedback you provide helps us identify the most and least reliable cars, and contributes directly to how we rate both new and used models in our car reviews.

Which? Car Survey 2026: now open

Tell us about your car and be in with a chance of winning £2,500 (T&Cs apply). Survey closes 10am on 17 June, 2026.

Take part now

About the Which? car survey

Whether your car has been plagued with faults or runs flawlessly, we want to hear about it.

Our in-depth lab tests reveal a car’s strengths and weaknesses, but they won’t tell us what it’s like to live with – and that’s where you come in.

Thanks to the information you share with us, we can reveal which are the least and most reliable cars and most reliable car brands. It also helps us identify what faults each car is likely to have. 

So when the time comes to buy your next car, you can use our research to avoid an unreliable model that's going to leave you with costly repair bills, or worse, stranded at the side of the road.

How the Which? car survey helps you

Once the results are in, we update our online advice, including: 

• New and used car reviews - every review and score is updated with the latest reliability information. This means you'll know which cars you can trust, and those you can't.
• Most reliable cars - our interactive tool reveals the most common faults for hundreds of new and used cars, giving you an idea of how much you're likely to fork out for repair bills.
• Most reliable car brands - we'll help you choose a car brand you can rely on.
• Best cars - our car experts will help you quickly pick the very best car for your needs, across all our car classes. Plus we reveal the models you should steer clear of.

Finding the most reliable car

Whether you’re buying a new car or something a little older, we can help you find a model you can rely on.

We dig as deeply as we can into each car’s track record, going back up to 15 years. To make sure we rate cars fairly, we classify every fault we hear about as one of the following:

• Most-serious faults are major problems that are likely to result in a breakdown, are expensive to repair and likely to lead to the car being off the road for more than one day
• Serious faults are likely to result in a breakdown and will either be expensive to fix, or keep the car off the road for more than a day
• Medium-rated faults are likely to cause a breakdown, but not be expensive or time consuming to repair
• Less-serious faults are unlikely to require immediate repair work, but could still be costly to fix
• Least-serious faults are non-essential problems that require less than a day off the road, and are cheap to put right.

When manufacturers ask why a car has scored poorly in the survey, we share as much detail as we can to help them get to the root of a problem. So these results not only help us compare different cars, they also give carmakers a reason to keep improving their vehicles.

The best cars to drive in the UK

Satisfaction counts for a lot when it comes to customer loyalty. A happy owner is likely to buy another car from the same manufacturer and wholeheartedly recommend it to others.

That’s precisely why our survey asks owners to rate (out of five) how satisfied they are with their car, and also how likely they are to recommend it to a friend. By combining the responses to these two questions, we’re able to award each car a customer score as a percentage.