25 most unreliable new cars

Some cars motor along for years without missing a beat, but others are afflicted by fault after fault. Here's our round-up of the most problematic 25 cars aged up to four years old...

25 most unreliable new cars 2018
Author Avatar
Claire Evans
20 Dec 2018 16:40

We asked more than 18,000 car owners to tell us how dependable their cars had been over the previous 12 months. A third of respondents told us their car had suffered at least one fault.

To categorise the faults and rate them for seriousness, we asked car owners to pick the area where the fault occurred from one of 14 groups: battery, bodywork, brakes, engine, engine electrics, exhaust, exterior lights, fuel system, gearbox/clutch, interior trim, non-engine electrics, steering, suspension and other.

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. We used this information to create the unique What Car? reliability rating, which penalises models that have lots of expensive faults and rewards dependable ones with a higher score.

Our full survey results reveal the dependability of 159 models from 31 car brands.

In reverse order, here are the least dependable cars aged up to four years old. 

Citroen C4 Picasso

25. Citroen C4 / Grand C4 Picasso (2013-2018) 

Score 86.2%

Nearly a third of Citroën C4 Picassos had a fault, with non-engine electrics by far the most frequently reported problem area, followed by engine electrics. Most spent less than a week in the garage. A few owners were presented with repair bills of up to £300.

Read our full used Citroen C4 Picasso review

Get a great deal on a new Citroen C4 Spacetourer with What Car?'s New Car Buyer service

Land Rover Discovery

24. Land Rover Discovery (2015-present)

Score 85.9%

A shocking 40% of Discoverys suffered a problem, according to owners. The most commonly afflicted areas were non-engine electrics and sat-nav systems, but there were also reports of issues with suspension, engine electrics, the fuel system and bodywork and trim. Most cars remained drivable, though, and almost all were fixed for free under warranty.

Read our full Land Rover Discovery review

Get a great deal on a new Land Rover Discovery with What Car?'s New Car Buyer service


Volkswagen Polo

23. Volkswagen Polo (2009-2017)

Score 85.8%

Only 21% of Volkswagen Polos had a problem. The most common issues related to non-engine electrical systems (7%), followed by air-con (5%), engine electrics (4%) and gearbox/clutch (3%). More than half the cars with faults were rendered undrivable, though, and a small number of owners had to pay bills of up to £1500.

Read our full used Volkswagen Polo review

Get a great deal on a new Volkswagen Polo with What Car?'s New Car Buyer service

BMW 5 Series

=22. BMW 5 Series (2017-present)

Score 85.3%

Owners told us 30% of their BMW 5 Series cars had a fault. Non-engine electrics were most prolific (13%), followed by interior trim (11%). Most were back on the road in less than a week, but some cost up to £500 to fix.

Nissan Qashqai

=22. Nissan Qashqai petrol (2014-present)

Score 85.3%

The petrol Qashqai isn’t quite as unreliable as the diesel; however, 46% of  petrol models had a problem. Although the faults weren’t as widespread as on the diesels, a large proportion were on the battery (19%) and engine (12%). Engine electrics accounted for 8% and non-engine electrics 6%. More than half of cars could still be driven, but some owners faced bills of up to £500.

Read our full Nissan Qashqai review

Get a great deal on a Nissan Qashqai with What Car?'s New Car Buyer service

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