25 most unreliable cars

While some cars never go wrong, others are afflicted by numerous faults. Here's our round-up of the most problematic models aged up to five years old...

25 most unreliable cars

One in five of the cars owners told us about in our most recent Reliability Survey suffered at least one fault. That's more than 2500 of the 13,000 cars surveyed. 

To help rate those faults for seriousness, we divided them into 15 categories: air-con, battery, bodywork, brakes, engine, engine electrics, exhaust, fuel system, gearbox/clutch, interior trim, non-engine electrics, sat-nav, steering, suspension and other. The most frequent area where problems were cited was non-engine electrics, with 27% of owners reporting this type of fault. 

We also asked owners to tell us how long their car was off the road while it was getting fixed and how much the repairs cost. While the majority of faults cost £100-£500 to put right, 2% of owners paid more than £1500. 

Combined, this information enabled us to create a unique reliability rating for each of the 175 models (from 31 different brands) featured in the survey. As you'd expect, cars that have lots of expensive faults receive the lowest scores, and the highest ratings go to the dependable ones that suffer no or only minor faults and that are cheap and quick to repair.

Below we count down the least dependable 25 models aged up to five years old.

The 2021 What Car? Reliability Survey is open now. Tell us about your car here >>

The most unreliable cars

25. MG ZS EV  (2019-present)

MG ZS EV driving

Reliability rating: 89.4%

The ZS EV isn't proving to be the most dependable electric car. Although only 7% went wrong, all of those were rendered undriveable and took more than a week to repair. Problem areas included the battery, electric motor and non-engine electrics. The good news is that all of the faulty cars were fixed under warranty.

Read our full MG ZS EV review >>

24. Jaguar E-Pace (2017-present)

Jaguar E-Pace

Reliability rating: 88.4%

E-Pace owners reported that 22% of their cars had suffered a fault, with the engine and its electrical components being the main culprits. There were also issues with non-engine electrical systems, including the air-con and infotainment, and some problems with the brakes, gearbox/clutch and fuel system. Although two-thirds of the afflicted cars could still be driven, a third languished in the garage for more than a week. While 93% of repairs were done for free, a small percentage of owners paid up to £750.

Read our full Jaguar E-Pace review >>

23. Kia Picanto (2017-present)

Kia Picanto front tracking - 69 plate

Reliability rating: 88.3%

Although 31% of Picantos went wrong, the most common problems were minor, relating to the battery and non-engine electrical systems. A third of the affected cars took more than a week to put right, but two-thirds of all work was done under warranty.

Read our full Kia Picanto review >>

22. BMW X6 (2014-2019)

Deal of the day: BMW X6

Reliability rating: 88.2%

Just over 31% of X6s went wrong, with gearbox issues being the most common complaint, accounting for 19% of faults. Other problematic areas included the exhaust, infotainment, interior trim and non-engine electrics. All of the troubled cars could still be driven, but one in five took more than a week to repair. Three-quarters of work was done for free, but owners who had to pay were faced with bills ranging from £50 to £750.

Read our full used BMW X6 review >>

21. Nissan X-Trail (2014-present)

Nissan X-Trail 2019 front tracking

Reliability rating: 87.6%

Owners told us that 34% of their X-Trails had suffered a fault, with the main areas of concern being engine and non-engine electrics. Other troublesome components included the brakes, engine and fuel system. Two-thirds of those cars were driveable and the problem was rectified in a day or less, the others took more than a week to put right. While three-quarters of work was done under warranty, some owners were faced with bills ranging from less than £50 to £1500.

Read our full Nissan X-Trail review >>

20. Vauxhall Insignia Grand Sport (2017-present)

Vauxhall Insignia Grand Sport

Reliability rating: 87.4%

A quarter of Insignia owners reported a fault on their car, with the gearbox/clutch causing the most concern. Other problem areas included the bodywork, engine, engine and non-engine electrics and the suspension. Nearly half of the cars couldn’t be driven and were out of action for more than a week. Thankfully, four out of five were fixed for free.

Read our full Vauxhall Insignia review >>

19. Mercedes C-Class (2014-present)

2019 Mercedes C-Class front

Reliability rating: 87.3%

Of executives car aged up to five years old, the C-Class was the lowest-rated for reliability. A third of them have gone wrong, according to owners, who reported a wide range of issues. One in four cars was off the road for more than a week, and although 81% of cars were fixed for free, a small percentage of owners paid out more than £1500 in repair bills.

Read our full Mercedes C-Class review >>

18. Nissan Qashqai (2014-2021)

Nissan Qashqai 1.3 DIG-T N-Connecta [Executive Pack]

Reliability rating: 87.0%

Few of the cars we were told about had a higher proportion of faults than the Qashqai, with 40% of them going wrong. The battery and non-engine electrical systems caused the most problems, followed by the brakes, exhaust and interior trim. Most of the stricken cars could still be driven, but more than a quarter spent a week or longer in the garage. On the bright side, four out of five of them were fixed for free and no repair bills topped £300.

Jaguar XJ front - bright blue

Reliability rating: 86.6%

A disappointing 43% of XJs had a fault, according to owners, with the battery and infotainment systems being the most problematic. Other troubles centred on the bodywork, engine, interior trim, non-engine electrics and suspension. However, the good news is that 60% of the afflicted cars could still be driven, 44% were fixed in a day or less and all work was done for free.

Read our full Jaguar XJ review >>

16. Ford S-Max (2015-present)

Ford S-Max

Reliability rating: 86.5%

Although 36% of the S-Maxes surveyed went wrong, the area most cited by owners wasn't a serious one – namely, bodywork. That was followed by the battery and non-engine electrics. There were also a smaller number of issues relating to the fuel system and infotainment/sat-nav. All of the affected cars could still be driven, and two-thirds were repaired in less than a week, with all costs covered by the warranty.