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25 most unreliable cars

While some cars remain dependable as years pass, others are afflicted with a wide range of faults. Here we take a look at the worst offenders up to five years old...

25 most unreliable cars

One in five of the cars owners told us about in our 2021 Reliability Survey suffered at least one fault. And while that means the odds of getting something dependable are in your favour, there are plenty of models that greatly increase the chances of your repair bills racking up quicker than you can ask a passenger whether they heard a strange noise.

Here, then, we're going to do our best to help you avoid such a fate, by counting down the 25 worst performers in our survey. Our scores take into account the number of faults, the cost of repairs and how long vehicles were off the road.

​​The 2022 What Car? Reliability Survey is now open. Tell us about your car for the chance to win a great prize in one of our monthly draws >>

25. Vauxhall Mokka X (2016-2019)

Vauxhall Mokka X

Reliability rating: 87.3%

A worrying 44% of Mokka Xs developed a fault, most commonly with either the air-con or the sat-nav system. Eighty per cent of cars could still be driven, but it took more than a week to fix the 20% that broke down, as well as 10% of those that didn’t. Furthermore, only 60% of work was done for free, leaving most owners with bills of up to £200, while 10% of owners were billed between £1001 and £1500.

Read our used Vauxhall Mokka X (2016-2019) review >>

=23. Nissan Qashqai diesel (2014-2020)

Nissan Qashqai 1.5 dCi N-Connecta

Reliability rating: 86.6%

The previous-generation diesel Qashqai comes out with a score 4.1% lower than petrol-powered versions, thanks to a 38% fault rate. Most problems were the result of battery failure, but the bodywork was also problematic for many. Thirty per cent of cars couldn’t be driven as a result, but all these were fixed within a week, and only 10% of cars took longer to repair. 

However, 30% of owners had to pay for repair work, with 10% paying between £51 and £100, and 15% paying between £101 and £200. The remaining 5% were billed between £301 and £500.

Read our used Nissan Qashqai (2014-2020) review >> 

=23. Vauxhall Astra (2015-present)

2019 Vauxhall Astra front

Reliability rating: 86.6%

Thirty-two per cent of Astras went wrong, mostly due to faulty non-engine electrics. There were also complaints about the battery, engine, gearbox/clutch and the interior trim.

Eleven per cent of cars couldn’t be driven because of their faults, but a dreadful 67% took more than a week to be fixed. Even worse, 6% of owners had to pay more than £1500 – rubbing salt in the wound.

Read our full Vauxhall Astra review >>

22. Jaguar I-Pace (2018-present)

Electric Car of the Year Awards 2021 - Jaguar I-Pace

Reliability rating: 86.3%

The Jaguar I-Pace has the lowest reliability score of all the electric cars in our survey, with 30% of cars going wrong. Most owners ran into issues with the 12-volt battery, sat-nav and non-motor electrics, and 45% of faults were severe enough to cause a breakdown and take more than a week to repair.

Shockingly, 75% of all faulty I-Paces took more than a week to fix, at great inconvenience to owners. It's fortunate that every issue was repaired under warranty – bills would have added insult to injury.

Read our full Jaguar I-Pace review >>

21. Audi A6 (2018-present)

Audi A6 2022 front right tracking

Reliability rating: 85.3%

Forty-seven per cent of A6s went wrong, thanks in large part to problems with the electrical systems – both related to the engine and otherwise – and the bodywork. The engine and sat-nav were also common areas of concern. Only 4% of cars were rendered undriveable by their faults, but 37% of cars suffered severe glitches that took longer than a week to repair. Most repairs were covered under warranty, but 7% of owners were left with a bill between £201 and £300.

Read our full Audi A6 review >>

20. Peugeot 3008 diesel (2017-present)

Peugeot 3008 2021 front

Reliability rating: 85.2%

While only 28% of 3008 diesel owners ran into issues, most commonly with the suspension, battery, or brakes, it’s the time and cost of repairs that lets the car down. Sixty per cent of cars suffered serious faults that required more than a week to fix, and 13% of owners were charged. Half paid between £101 and £200, while the other half paid shocking bills of between £751 and £1000.

Read our full Peugeot 3008 review >>

19. Mercedes A-Class (2018-present)

Mercedes A-Class front corner

Reliability rating: 84.8%

Once one of the top scoring family cars in our 2020 survey, the Mercedes A-Class’s rating deteriorated significantly with the introduction of a new model. The current version is this year’s least reliable family car, with 31% going wrong.

Most of the affected cars encountered issues with faulty non-engine electrics, but the interior trim and air-con were also cited as problematic, which is disappointing from a premium brand. The service wasn't great either: 36% of owners had to wait more than a week for repairs, 8% were billed between £501 and £750, and 3% had to pay more than £1500 to get their cars working again.

Read our full Mercedes A-Class review >>

18. Fiat Abarth 124 Spider (2016-2019)

Fiat 124 Spider

Reliability rating: 84.5%

Thirty-three per cent of 124 Spiders ran into issues, with electrical bugs forming the majority of problems, followed by bodywork and engine woes. Service was mixed: 46% of cars were repaired within a week, but 36% took longer, indicating a severe fault. Costs were at least kept low, with 91% of repairs carried out for free. As for the remaining 9%, nobody paid more than £200, but those bills soon rack up over years of ownership.

Read our full Fiat Abarth 124 Spider review >> 

17. Nissan Juke petrol (2010-2019)

Nissan Juke

Reliability rating: 83.8%

Unconventional styling made the original Nissan Juke something of a Marmite car in its time – you either loved or loathed it – and if you pick a petrol-engined model you’re more likely to be one of the haters. Thirty-seven per cent of petrol-engined Jukes had a fault, most commonly with the battery or bodywork, but the engine and suspension were also problem areas. 

Most (79%) repair work was done for free, but 7% of owners paid up to £50, another 7% between £101 and £200, and the remaining 7% saw bills as high as £750. While no cars broke down because of any issues, the Juke’s record was further tarnished by the fact that 36% of owners waited more than a week for their car to be repaired.

Read our full used Nissan Juke (2010-2019) review >>

16. Range Rover Sport diesel (2013-present)

Range Rover Sport '15 plate front corner

Reliability rating: 83.5%

The Range Rover Sport features on this list once again this year, although its score is 9.3% better than last time. Its failure rate was fairly consistent at 39% (1% less than last year) and the engine and non-engine electrics were once again problem areas, joined by sat-nav glitches.

The service wasn’t great either. Repairs took more than a week in 40% of cases, and only 87% of cars were fixed for free – with 3% of owners getting bills between £1001 and £1500. 

Read our full Range Rover Sport review >>