Which? urges car makers to up their game on reliability as new research reveals electric vehicles are the most fault-prone fuel type

Which? is calling on car manufacturers to improve the reliability of electric vehicles (EV) after the consumer champion found EVs are the least reliable fuel type and spend longer off the road than other cars when they need repairs. 

A Which? survey found that of cars up to four years old, nearly one in three (31%) EV owners reported one fault or more, compared to less than one in five (19%) petrol cars. Owners of those faulty electric cars then went an average of just over five days without the use of their car while it was being fixed – compared to just three days for petrol cars.  

However, it’s not all doom and gloom for drivers who want to move to a more sustainable vehicle. Among cars four years old or less, the Kia e-Niro (2019- present), which starts from £32,895, was found to be the most reliable EV and also the most reliable small or compact SUV of any fuel type – one of the most popular classes of car on the market. 

Just one in every 17 (6%) e-Niro owners reported any kind of fault with their car and only one in 100 (1%) said their car had failed to start or broke down. However, the unlucky few who did have an issue faced an average of around eight and a half days off the road, showing there is still work to do on improving repair times when things do go wrong.

In spite of the high fault rates reported by EV owners in the survey, Kia has proven that electric cars have the potential to be very dependable. Which? is calling on other car makers to up their game and improve the quality of their cars. Manufacturers need to gain the trust of drivers to encourage them to switch towards more sustainable cars.

There is potential for manufacturers to improve as there are fewer moving parts in EVs than in other fuel types. The most common faults raised by EV drivers in the survey were software problems, not motor or battery pack issues. There are also reliable, partly-electric cars available on the market today. Which?’s survey found that the most reliable cars of any fuel type are full hybrids*, with just one in six (17%) owners reporting a fault among cars aged up to four years old.

The annual Which? car survey is one of the largest motorist surveys assessing car reliability in the UK, collecting detailed feedback from over 48,000 vehicle owners. The survey asked owners if there had been any faults with their cars in the 12 months prior to answering.

Despite their most expensive model costing up to more than two and a half times more than the e-Niro, Which?’s survey also found that Tesla is the least reliable EV brand. In cars up to four years old, two fifths (39%) of Teslas had at least one fault and one in 20 (5%) had a breakdown or failed to start. 

Which? has previously called for the Tesla Model S (2013- present), which starts from £79,980, to be recalled over issues with its door handles and locks for two years running. A positive for Tesla is that its cars were only off the road for just under three and a half days on average when they needed repair work.

As well as calling for an improvement in EV reliability, Which? has also recently called for the quality and provision of charging infrastructure to be significantly improved. A recent policy paper from the consumer champion calls for improvements in the accessibility and the experience of using the public charging infrastructure. 

Having confidence in both electric vehicles and the infrastructure to charge them is crucial to support drivers to choose a more sustainable car.

Lisa Barber, Which? Home Products and Services Editor, said: 

“We know that drivers are keen to make the move to more environmentally-friendly cars but it is vital that they are getting a quality product. Whilst it’s disappointing to see that EVs as a group are the least reliable, Kia’s e-Niro shows there is a significant opportunity for manufacturers to up their game and provide drivers with a reliable and more sustainable car. 

“With EVs in particular, our research shows a premium price tag does not necessarily mean a reliable vehicle, so we would always encourage drivers to do their research ahead of such a significant purchase to see which cars and brands they can trust.”



Notes to editors:


Car fault and breakdown/failed to start rates by fuel type:

Cars aged 0-4 years Cars with one fault or more Cars with one or more breakdown/failed to start Average days off the road (over 12 month period)
Overall 22.3% 4.9% 3.6
Full hybrid* 17.3% 5.6% 3.9
Petrol 18.6% 3.5% 3
Plug-in hybrid 27.5% 5.4% 4.2
Diesel 29.1% 6.9% 3.8
Electric 31.4% 8.1% 5.1


*Full hybrids are the most common type of hybrid. They recharge from the main combustion engine, you cannot charge them from a socket like a plug-in hybrid (PHEV).

Source: 2021 Which? Car survey: UK survey in field from April to July 2021. 48,034 respondents told Which? about 56,853 cars they own and drive.


How Which? assesses individual car model reliability: 

Which?’s reliability measure includes (but is not exclusive to) the proportion of cars that experienced a fault, the number of faults experienced, the severity of fault, the outcome of the fault (including whether the car would start was still drivable, broke-down, was unsafe to drive etc), as reported by owners of the cars. The survey asks about any faults that occurred in the 12 months prior to answering. The reliability score also considers the time the owner spent without the use of their car while it was being repaired. Which?’s reliability score is applied to cars across three age groups: 0-4 years, 5-9 years and 10-15 years. All data from the Which? 2021 car survey (UK survey, in field between April 2021 and June 2021. 48,034 owners told us about 56,853 cars).


Which?’s position on EV infrastructure: 

Which? calls for electric vehicle charging overhaul as new research reveals drivers only use public network for 13% of charging


About Which? 

Which? is the UK’s consumer champion, here to make life simpler, fairer and safer for everyone. Our research gets to the heart of consumer issues, our advice is impartial, and our rigorous product tests lead to expert recommendations. We’re the independent consumer voice that influences politicians and lawmakers, investigates, holds businesses to account and makes change happen. As an organisation, we’re not for profit and all for making consumers more powerful.

The information in this press release is for editorial use by journalists and media outlets only. Any business seeking to reproduce information in this release should contact the Which? Endorsement Scheme team at endorsementscheme@which.co.uk

Press Release: , ,