Reliability Survey: Most and least reliable petrol cars

Petrol cars may be phased out in just over a decade with the 2035 ban on non-electric models, but they’re still a great choice for many motorists. Many of the latest models are kitted out with clever technology, such as mild hybrid systems, that improve economy and enhance performance. This means petrol cars can be almost as frugal on fuel as their diesel counterparts. 

A petrol model is also a good choice if you want a dependable vehicle. According to our survey, only 20% of petrol cars suffered a fault in the past 24 months, that’s 6% lower than the fault rate for diesel and pure electric models.  This means that many petrol cars cost less in repair bills than their diesel siblings, and they spend less time in the garage getting fixed.    

How the research was carried out

The latest What Car? Reliability Survey contains information from 21,732 car owners on how reliable their car has been over the previous 24 months. To start, we asked them to tell us if the car had suffered any faults, and, if so, how much each one cost to put right and how long it kept the car off the road. 

We used these two factors to create a reliability rating for each brand and model. The survey, conducted in association with MotorEasy, contains data on 178 models aged up to five years old from 32 different car brands.

The 2024 What Car? Reliability Survey is live, tell us about your car now

Most reliable petrol cars 

=1. Hyundai Tucson (2015-2020)

Reliability rating 100%

The 2015-2020 Hyundai Tucson was offered with two 1.6-litre petrol-engines: a 133bhp non-turbo unit and a 174bhp turbocharged version that is our preferred choice because it has more pulling power. However, whichever Tucson you go for, it’s likely to have very few problems: not a single petrol Tucson owner reported a fault with their car in the previous 24 months.  That meant no unexpected repair bills or time off the road. 

=1. Mazda CX-3 (2016-2021)

Reliability rating 100%

The 2016-2021 CX-3 is a good-looking small SUV that’s also rewarding to drive, especially the versions with lively 2.0-litre petrol engines. It’s also well-equipped, even the entry-level SE Nav comes with air-con, cruise control and a 7.0in touchscreen infotainment system with sat-nav. It should be dependable too, because none of the CX-3s reported on in our survey had any issues.  

=1. Mini Countryman (2017-2023) 

Reliability rating 100%

Mini’s small SUV is also proving extremely robust, with a fault rate of zero in our survey. The 2017-2023 Mini Countryman comes with a choice of petrol or diesel power and as a plug-in hybrid. All have punchy performance and neat handling, and as the biggest Mini model, the Countryman also offers plenty of room for four adults in the well-appointed interior.   

Least reliable petrol cars

1. Jaguar E-Pace (2017-present) 

Reliability rating 72.7%

The Jaguar E-Pace is the lowest scoring petrol model in our latest survey, with owners telling us 33% of their cars had issues. The gearbox/clutch and sat-nav system were the most common bugbears. These and other problems kept 43% of cars in the garage for more than a week. The only positive points are that all issues were sorted out for free, and petrol models went wrong less often than diesels, which have a fault rate of 44%.  

2. BMW 4 Series Coupe / Convertible (2013-2020)

Reliability rating 75.0%

Petrol versions of the 2014-2020 BMW 4 Series went wrong more often than their diesel counterparts: 24% of petrol cars had a problem compared with 14% of diesels. However, the problems were mostly with the 12-volt battery or bodywork rather than any mechanical components. Although most cars could still be driven, two-thirds took more than seven days to fix.    

3. Alfa Romeo Giulia (2016-present)

Reliability rating 76.6%

Almost half (47%) of the petrol-engined Alfa Romeo Giulia cars we were told about had a glitch; that’s 14% more woes than diesel models suffered. The engine and 12-volt battery were the most common causes of concern. Three-quarters of cars could still be driven, but 31% were out of action for more than a week. Thankfully Alfa covered the cost of all remedial work.  

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 petrol cars aged up to five years old

Least reliable petrol cars aged up to five years old

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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