Which? Car Survey explained


Which? Car Survey explained

By Adrian Porter

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How does Which? identify the most reliable cars? It’s thanks to the tens of thousands of people who tell us about their cars in our annual survey.

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Whether you’re after the best family car, best small car or best sports car, what makes a car great is that it gets you from A to B without breaking down.

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

Every year, tens of thousands of people complete our annual Which? car survey. The information you provide is crucially important, as we use it to find the most reliable cars for sale. It also means we can warn people about the most unreliable vehicles – the ones that leave you stranded on the side of the road with lots of time to contemplate the annual four-figure repair bill.

To see the cars that excelled in the Which? test lab check out our Best Buys.

Finding the most reliable cars

Our survey is unique because we ask about cars of all ages. That means whether you’re buying a brand-new car or a banger, our comparative owner feedback will help you make a better choice.

We dig as deeply as we can into each car’s track record, going back a maximum of eight years. So that we rate cars fairly, every fault we hear about is classified as one of the following:

Most serious faults: these 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: 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: likely to cause a breakdown but not be expensive or time-consuming to repair.

Less serious faults: unlikely to require immediate repair work but still costly to fix.

Least serious faults: 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 evolving and improving their products.

Best cars to drive in the UK

Satisfaction counts for an awful 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 response to these two questions, we’re able to award each car a customer score as a percentage.

Which? 2016 Survey

The 2016 Car Survey is now closed. Eager to tell us about your car? The 2017 car survey will open in December 2016 and run until February 2017. But to keep you going until then, here are some interesting facts from the 2015 survey:

  • We received data on 57,918 cars in total from 49,001 owners (some have more than one car).
  • Owners reported on a total 20,500 faults (for cars up to eight years old).
  • Those who filled in the survey covered a total of 483,668,000 miles - enough to circumnavigate the globe 22,392 times, or to go to the moon and back a hundred times.
  • 91% of respondents who had bought a car in the past 12 months had purchased it as new.
  • The average annual mileage of people who filled in the survey is 8,707 miles.