Reliability survey: the most expensive cars to fix, and the cheapest

According to the findings of the latest What Car? Reliability Survey, 83% of cars aged up to five years old were fixed for free, either under their new car warranty or as a goodwill gesture by the car maker. 

However, that leaves an unfortunate 17% who had to cover the costs themselves. While most of those car owners only had to find up to £500 to get their cars repaired, 2% had to pay more than £1500 for each fault. 

When it comes to costly repairs, it’s diesel versions of the current BMW 3 Series which are the worst; 42% of the examples in our survey cost more than £1500 to repair. In total, those BMW 3 Series owners surveyed each paid out an average of £421 to get their cars put right. 

The most common issues across all cars aged up to five years old were electrical glitches with the infotainment and sat-nav systems, but owners also told us their cars had suffered problems with the bodywork, engine, exhaust and fuel systems and the gearbox/clutch.  

Although 34% of faulty cars could still be driven and were fixed in a day or less, 28% of driveable cars took more than a week to repair, and 10% were undriveable and took more than a week to fix.  

How the research was carried out

The latest What Car? Reliability Survey, conducted in association with MotorEasy, gathered ownership data from 21,732 car owners. Each one told us how reliable their car had been over the previous 24 months. 

First we asked them to tell us if the car had suffered any problems, and, if so, how much each one had cost to put right and how long it had kept the car off the road. This data was used to create a unique reliability rating for 178 models aged up to five years old from 32 different car brands.

To work out which are the most costly and cheapest to fix, we’ve taken the amounts owners told us they’d paid to get their cars fixed — that’s anything from £1 to more than £1500 — and added them all together for each model. We’ve then divided that figure by the number of cars reported on for each model to get an average repair cost. Where we have enough data we’ve separated out diesel, electric, hybrid and petrol versions of each model.  

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The most expensive cars to fix 

1. BMW 3 Series diesel (2019-present)

Average repair cost £421

Diesel versions of the current BMW 3 Series are far more prone to faults and costly to repair than petrol models. Almost a third (30%) of the diesel models reported on had a problem, compared with 11% of petrol cars. Worse news for diesel owners is that 56% of their cars’ faults cost more than £1500 to put right, and that meant the owners in our survey paid out an average of £421 in repair bills. Owners of petrol-powered 3 Series cars are a more contented bunch because all their cars were fixed for free. 

2. Audi A1 (2018-present) 

Average repair cost £218

The Audi A1 is the most expensive small hatchback when it comes to repairing faults. Although Audi covered the cost of 50% of issues, 17% of owners were left with bills ranging from £310 to £500, and 33% had to pay more than £1500 to get their cars fixed. In contrast, Ford paid for all repairs on the recently discontinued Fiesta. Audi A1 owners told us 25% of their cars had gone wrong in the previous 12 months, and that half of faulty cars were out of action for more than a week. 

3. Audi A3 (2013-2020) 

Average repair cost £100

There’s a stark contrast between 2013-2020 Audi A3 repair bills: 89% of cars were fixed for free, but all the rest set their owners back more than £1500 in costs. The current A3 is proving less costly to own, with 96% of bills covered by Audi and none of the remaining bills topping £300. According to our data, 275 of previous generation A3s went wrong, and 40% of them were in the workshop for more than a week. 

4. Kia EV6 (2021-present) 

Average repair cost £94

The Kia EV6 is the priciest electric car for fault repairs. Owners told us 24% of their EV6s had an issue, and while 86% of cars were fixed for free, the remaining 14% cost between £1000 and more than £1500. Three-quarters of faulty cars took more than a week to fix, too. 

5. Mercedes E-Class (2016-2024)

Average repair cost £83

The 2016-2024 Mercedes E-Class has been more expensive to live with than rivals, such as the 2017-2023 BMW 5 Series. Twenty percent of E-Class owners had to foot the bill for repairs to their cars, and whilst 10% of them between £201 and £300,  the rest were charged more than £1500, pushing the average repair cost up to £83. In contrast, BMW fixed all faulty 5 Series models for free. Some good news for E-Class owners: two thirds of faulty cars were repaired and back on the road in less than a week. 

6. Range Rover Evoque (2019-present) 

Average repair cost £82

Although Land Rover paid for 93% of remedial work on faulty Range Rover Evoque models, the remaining 7% of owners all had to shell out more than £1500 to get their cars fixed. Defender, Discovery and Range Rover Sport owners fared better, because Land Rover covered the cost or all repair to their vehicles. While a third of cars were repaired in a day or less, almost half sat in the garage for more than a week. 

7. Mercedes A-Class hybrid (2018-present)

Average repair cost £73

While Mercedes paid for all repairs on petrol and diesel A-Class models, it left 10% of hybrid owners with bills of more than £1500, making this the most expensive version of the car to live with. Thirty percent of the A-Class hybrids reported on went wrong, althoug the good news is that only 18% of faulty cars spent more than a week in the workshop. 

8. Audi Q5 (2018-present)

Average repair cost £71

Eleven percent of Audi Q5 owners had to pay for their cars to be fixed, they paid out between £751 and £1000 per fault. Audi paid for the repairs on the remaining 89% of faulty cars. Overall, 35% of Q5s had glitches, and while most cars could still be driven, 42% were out of action for more than seven days. 

9. Hyundai Ioniq 5 (2021-present)

Average repair cost £62  

The Ioniq 5 is a big electric SUV that’s almost as large as an Audi Q5. On average it costs £9 less than the Q5 to fix its faults. According to our data, 83% of repairs cost owners nothing, but 17% cost them more than £1500. A third of issues were resolved in a day or less, but 50% of cars spent more than a week in the garage. 

10. Volkswagen Golf (2020-present) 

Total repair cost £56

While 89% of current generation Volkswagen Golf models were repaired for free, a small percentage of owners had repair bills that ranged from £751 to £1500. That pushed the average paid out by them to £56. They’ve fared much worse than owners of the 2013-2020 Volkswagen Golf, because all the examples of this model in our survey were repaired at no cost to the owners.  

Cheapest cars to fix

When it comes to covering the cost of fault repairs, some brands go all out and pay for everything. Those that paid for all repairs of vehicles aged up to five years old in our survey were Alfa Romeo, Citroen, Dacia, Lexus and Polestar.  

To be fair, the only Alfa Romeo model we had enough data to report on specifically was the Giulia, whose owners told is 44% of their cars had suffered issues, mostly with the electrics. However, it's reassuring to know that all issues were resolved for free, especially as many faulty cars would have been outside their three-year new car warranty period. 

It's no surprise to see Lexus in the list of brands to fix all faults for nothing because it's been the overall champion for reliability for the past six years — and our reliability ratings are based on how cheaply and swiftly any issues are dealt with by the car maker. While most Lexus models, such as the NX and RX had very few faults (the current NX had a 5% fault rate and the RX had 8%), 20% of the ES saloons reported on encountered a problem, but Lexus dealers still sorted out all their issues gratis. 

Another newer premium brand, Polestar, is also looking strong for customer service: whilst 42% of Polestar 2 models had a problem, all were fixed for free. 

However, you don't have to buy a premium model to get good aftersales care, as Citroen and Dacia demonstrate. Owners of C3 Aircross and C5 Aircross models told us Citroen covered the cost of all repairs on their cars, and all faulty Dusters and Sanderos were also put right without charge. 

To read the reliability data for other car classes follow these links:

All cars and SUVs here
Most reliable small cars
Most reliable family cars
Most reliable executive cars
Most reliable luxury cars
Most reliable small SUVs
Most reliable family SUVs
Most reliable large SUVs
Most reliable seven-seaters
Most reliable electric cars
Most reliable electric SUVs
Most reliable sports cars
Most reliable car brands
Most reliable diesel cars
Most reliable hybrid cars
Most reliable petrol cars

About the report author

Claire Evans has been a motoring journalist for more than 30 years, working on consumer issues for a great deal of that time. After a stint as the advice columnist for Carweek magazine in the 1990s, she also spent six years working on motoring content for Which?. It is here she oversaw the running of the charity's annual used car reliability survey.

Claire launched the What Car? Reliability Survey in 2017, and since then has helped thousands of buyers choose the most reliable new cars and SUVs, as well as the most dependable used cars.

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