What Car Reliability Survey: Most and least reliable petrol cars
In our annual Reliability Survey, we ask readers to rate the dependability of cars aged up to five years old. Here we list the most and least reliable petrol cars in the UK...
Petrol cars may be phased out in five years time with the 2030 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 22% of petrol cars suffered a fault in the past 24 months, that’s 9% lower than the fault rate for diesel models and 5% less than pure electric models.
Even better news is that petrol-engined models are among the cheapest for repair bills. According to owners, 79% of petrol cars were fixed for free. Only electric cars perform more dependably; 89% of which were repaired at no cost to owners. In contrast, only 67% of diesel repairs were done gratis.
This listing contains all the models up to five years old that are either offered only with petrol power or for which we have enough data to list petrol, diesel and hybrid versions separately.
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Most reliable petrol cars
1. Toyota Aygo X (2021-present)
Reliability rating 100%
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Most common faults: None
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Average repair cost: £0
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Typical time off road: n/a
The Toyota Aygo X is a small car that's affordable to buy, and is well suited to life in the city. It's one of only a handful of petrol-powered city runabouts you can still buy new; many small cars are now only available as electric models, which are far pricier to buy.
It's only offered with a 71bhp 1.0-litre petrol engine that’s free from any turbocharging or hybrid electrical assistance, so it's not the last word in red-hot acceleration. However, the Aygo X is nippy enough for town driving, has tidy handling, a tight turning circle, and slick gearchanges from the manual gearbox.
Toyota’s tiniest and most affordable car has outdone its bigger siblings with a perfect reliability rating of 100%, meaning not one of the Aygo Xs in our survey had any glitches, so not a single Aygo X owner in our survey needed to seek assistance from dealers at all in the previous 24 months.
Owner's comment: "Its superb reliability is the thing I like best about my Aygo X."
=2. Kia Picanto (2017-2024)
Reliability rating 99.3%
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Most common faults: Gearbox/clutch 6%
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Average repair cost: £0
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Typical time off road: 100% one day or less
Although you can't buy this generation of the Kia Picanto city car new any more, it's still a great secondhand option. It's good fun to drive, has a usefully roomy boot and it comes with a seven-year, 100,000-mile warranty.
There are three petrol engines to choose from: a 66bhp 1.0-litre, a 83bhp 1.25-litre, or a turbocharged 99bhp 1.0-litre. The 66bhp 1.0 is just about sufficient, the 1.25 is punchier and more refined, and the 1.0 turbo is the most sprightly of the trio.
Whichever engine you choose, you're highly likely to get a dependable motor because the Picanto is the second highest scoring small car for reliability. A mere 6% of examples aged up to five years old had any issues, and then only with the gearbox/clutch. Kia covered all repair costs, too, and its workshops resolved all problems in a day or less.
=2. Porsche Boxster / Cayman (2016-present)
Reliability rating 99.3%
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Most common faults: Bodywork 6%
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Average repair cost: £0
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Typical time off road: 100% one day or less
Although the Porsche 718 Boxster and Cayman are Porsche's entry-level sports cars, they're among the best you can buy and they're good value for money by the standards of the class. The way they balance performance and driving fun with everyday usability make them perfect for many buyers.
Both the Boxster and Cayman are a joy to drive and, if you go for the GTS version, you'll get a fantastic, sweet-sounding six-cylinder engine to match the superb dynamics.
They are the highest scoring sports car duo in our survey. Only 6% of the cars reported on had any glitches, and the only area of concern was the bodywork. Getting things fixed was easy, too, with all work completed in a day or less, and Porsche covered the cost of all the work required.
Reliability rating 99.3%
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Most common faults: Fuel system 6%
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Average repair cost: £0
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Typical time off road: 100% one day or less
In the not-too-distant past, our survey data would have contained lots of responses from diesel-engined Skoda Octavia owners. However, the dramatic demise in the popularity of this fuel type means we can only report on petrol versions of this highly practical family hatchback.
That's no bad thing though, because it's proving impressively durable as it ages. In fact, it's the most reliable family car, with a near-perfect rating. This makes it a much better bet than the latest Octavia, which has been blighted by a high percentage of electrical issues.
Just 6% of the cars in our survey suffered any glitches. All issues were inconsequential, too, because they didn’t cause any breakdowns and were put right in less than a day. Even better, all work was done for free.
5. Hyundai Kona (2017-present)
Reliability rating 98.7%
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Most common faults: Air-con 3%, exhaust 3%
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Average repair cost: £0
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Typical time off road: 50% one day or less, 50% more than a week
The petrol-engined versions of the Hyundai Kona are the most affordable fuel type, but in contrast to the general trend, they're more robust than their pure electric siblings. Only 3% of petrol Konas had a fault, compared with 23% of electric models.
Whichever Kona you go for you'll get plenty of equipment, a roomy interior and a good infotainment system. We'd recommend opting for a 2021-on facelifted model, as you'll get an all-new interior with more space, plus lots of new technology and equipment.
Demonstrating the value of the lengthy Hyundai new car warranty (five years/unlimited miles), all faulty cars were fixed for free. Although half of those cars were in the workshop for more than a week, the rest were back out on the road in a day or less.
6. BMW 4 Series Coupe / Convertible (2020-present)
Reliability rating 98.4%
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Most common faults: Non-engine electrics 8%, steering 3%
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Average repair cost: £0
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Typical time off road: 25% one day or less, 75% one day to a week
The BMW 4 Series is great to drive, smart inside and roomier than you might imagine. The seriously rapid M440i is great fun, the more mellow 420i strikes the best balance between performance and running costs, while still impressing on a twisty road.
When it comes to reliability, the latest 4 Series looks like a far better bet than its predecessor, which is the least dependable petrol model in this category.
Only 8% of the cars reported on suffered any problems, all concerning the steering and non-engine electrical systems. BMW paid for all repairs, and all faults were resolved in less than a week; 25% of cars were fixed in a day or less.
BMW 4 Series Coupe / Convertible review
7. Volkswagen Polo (2018-present)
Reliability rating 98.3%
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Most common faults: Bodywork 4%
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Average repair cost: 83% cost £0, 17% cost up to £50
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Typical time off road: 50% one day or less, 50% more than a week
The Volkswagen Polo is a great all-rounder that's smart, comfortable, roomy inside and good to drive. While it has a higher list price than some small cars, it holds onto its value well offsetting some of the additional cost.
It comes with a choice of three 1.0-litre petrol engines: 80, 95 and 110. The lowest-powered 80 is a bit weedy, so the mid-range 95 is our favourite because it offers decent acceleration and economy. The 110 costs more to buy and run.
Only 7% of Polo owners told us their cars had suffered any glitches, and the main cause for concern was the bodywork. There was also a small percentage of reports of issues with the gearbox/clutch and interior trim. Repairs were mostly carried out for free: Volkswagen covered the cost of 83% of work, and the remaining faults cost less than £50 each.
Remedial work could be slow, though. While 50% of cars were fixed in a day or less, the other 50% were in the garage for more than a week.
8. BMW 2 Series Coupe / Convertible (2014-2021)
Reliability rating 98.2%
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Most common faults: Bodywork 4%, engine 3%
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Average repair cost: £0
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Typical time off road: 50% one day to a week, 50% more than a week
Although the 2014-2021 BMW 2 Series and Convertible are based on the same platform as the 1 Series hatchback, they have a larger footprint making them a pretty practical proposition as four-seater transport.
A true driver's car, the 2 Series was offered with a wide range of petrol engines, starting with a frugal and fairly fast 1.5-litre, and going up to the M240i full-on performance car. Whichever version you choose, you should get a dependable car, though.
The 2 Series Coupe and Convertible are proving just as sturdy as their larger 4 Series siblings. Only 7% of cars went wrong, and all problems were fixed at no cost to the owners. The only slight niggle is that dealers were slow to fix cars: half were out of action for up to a week and the rest took more than a week to put right.
Reliability rating 98.0%
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Most common faults: Non-engine electrics 4%, exhaust 3%, steering 3%
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Average repair cost: 67% cost £0, 33% cost up to £50
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Typical time off road: 33% one day or less, 67% more than a week
The Volkswagen T-Cross is a roomy and versatile small SUV that's good to drive with decent fuel economy. It's offered with less powerful engines and less standard kit as VW's other SUVs, such as the Volkswagen Taigo coupe SUV and larger Volkswagen T-Roc, so it represents a more affordable option.
While the T-Roc has a slightly better reliability rating (98.4%) than the T-Cross, the Taigo is rated lower, at 94.7 and it has a far higher fault rate: 27% of Taigos had a problem compared with 10% of T-Cross and T-Roc models.
The only areas to give owners any grief on their T-Crosses were the exhaust, electrics and steering. Two-thirds of issues were rectified for free, and the rest cost £50 or less, but the majority of faulty cars took more than a week to fix.
10. BMW 3 Series (2019-present)
Reliability rating 97.5%
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Most common faults: Engine 2%, engine electrics 2%, non-engine electrics 2%
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Average repair cost: 89% cost £0, 11% cost £101-£200
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Typical time off road: 56% one day to a week, 44% more than a week
The BMW 3 Series is a well-built, sporty, rear-wheel-drive executive car that's long done the business for business people. Although the diesel engines were discontinued from the range in 2024, it's still offered with a good selection of petrol engines and a tax-friendly plug-in hybrid (PHEV).
Petrol versions of the 3 Series have fewer faults than diesel or PHEV models: our survey data reveals that 9% of petrol models went wrong, compared with 17% of diesels and 16% of PHEVs. Most issues (89%) were sorted for free by BMW and its dealers, and owners who had to pay only had to find less than £200 per fault.
The only fly in the ointment is that repairs could take some time. No problems were fixed in a day or less, and 44% of cars were out of action for more than a week.
Least reliable petrol cars
1. BMW 4 Series Coupe / Convertible (2013-2020)
Reliability rating 79.0%
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Most common faults: Bodywork 14%, 12-volt battery 7%, air-con 4%, brakes 4%, engine 4%, fuel system 4%, non-engine electrics 4%
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Average repair cost: 33% cost £0, 24% up to £750, 17% £1001-£1500, 8% more than £1500
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Typical time off road: 50% more than a week, 33% one day to a week
Sharp handling and smooth looks make the BMW 4 Series a desirable used coupe and convertible. The pair are based on the same underpinnings as the 3 Series saloon, which is a good thing because it means they're available with a wide range of strong petrol engines. However, they suffer from far more issues than their four-door cousin.
Costly repair bills and long stints in the workshop were the bugbears of the 25% of previous-generation 4 Series owners who told us their cars had gone wrong. Only 33% of fixes were done for free, leaving most owners with bills in the hundreds and 25% having to find more than £1000 to put things right. Half of the faulty cars took more than a week to fix.
Owner's comment: "My car has an ongoing issue; it’s now in the garage for the fifth time for the same fault."
Used BMW 4 Series Coupe / Convertible review
2. MG ZS (2017-present)
Reliability rating 81.1%
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Most common faults: Non-engine electrics 29%, sat-nav/infotainment system 16%, engine 10%, engine electrics 10% gearbox/clutch 7%
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Average repair cost: 89% cost £0, 8% cost £151-£200
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Typical time off road: 46% one day or less, 38% more than a week
The MG ZS family SUV is available with a choice of petrol and electric power. All versions are good value for money, and all come with a relatively upmarket interior, roomy rear seats, tidy handling and a long warranty.
However, neither the petrol nor electric models have been easy for all owners to live with. ZS Electrics have a fault rate of 43% and the petrol ZS is even worse, with 58% of cars suffering some sort of issue.
Althugh MG covered the cost of most repairs, some owners had to pay up to £200 per fault. Many also had to wait a long time to get their cars back: more than a third of faulty cars were off the road for more than a week.
3. Fiat 500 (2008-present)
Reliability rating 82.1%
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Most common faults: Engine electrics 16% exhaust 16%, gearbox/clutch 5%, non-engine electrics 5%, sat-nav/infotainment system 5%
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Average repair cost: 40% cost £0, 40% cost £501-£750
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Typical time off road: 50% one day or less, 50% one day to a week
Since it arrived in 2008, the reborn Fiat 500 has been a huge hit. Its cute design, Italian style and compelling affordability have resonated with both new and used car buyers. The 500 has been tweaked and updated many times, and the latest version, known as the 500 Hybrid, has a petrol engine aided by a small electric motor. You can't plug it in and charge up the battery and the car doesn't run on pure electric power, but it's nippy around town and economical. A pure electric 500 was added to the line-up in 2021.
Petrol versions of the Fiat 500 went wrong less often than the newer pure electric models: 26% of petrol 500s had a problem, compared with 33% of electric ones. The majority of faults on both models were with the electrics, but petrol cars also had issues with their engines and gearbox/clutch systems.
Remedial work was often swift, though. Half of the problems were resolved in a day or less, and all the rest were sorted in less than a week. Only 40% of repairs were done for free, leaving 40% of owners with bills of up to £750.
To read the reliability data for other car classes follow these links:
Most and least reliable cars overall (2024)
Most reliable car brands (2024)
Most reliable small cars (2024)
Most reliable family cars (2024)
Most reliable executive cars (2024)
Most reliable luxury cars (2024)
Most reliable small SUVs (2024)
Most reliable family SUVs (2024)
Most reliable large SUVs (2024)
Most reliable seven-seaters (2024)
Most reliable electric cars (2024)
Most reliable electric SUVs (2023)
Most reliable sports cars (2024)
Most reliable diesel cars (2023)
Most reliable hybrid cars (2023)
Most reliable petrol cars aged up to five years old
| Rank | Make and model | Score |
| 1 | Toyota Aygo X (2021-present) | 100% |
| =2 | Kia Picanto (2017 - 2024) | 99.3% |
| =2 | Porsche 718 Boxster/Cayman (2016-present) | 99.3% |
| =2 | 2013-2020 Skoda Octavia | 99.3% |
| 5 | Hyundai Kona (2017-present) | 98.7% |
| 6 | BMW 4 Series Coupe/Convertible (2020-present) | 98.4% |
| 7 | Volkswagen Polo (2018-present) | 98.3% |
| 8 | 2014-2021 BMW 2 Series Coupe/Convertible | 98.2% |
| 9 | Volkswagen T-Cross (2019-present) | 98.0% |
| 10 | BMW 3 Series (2019-present) | 97.5% |
| 11 | Toyota GR Yaris (2020-present) | 97.4% |
| =12 | Skoda Karoq (2017-present) | 96.7% |
| =12 | 2017-2023 BMW 5 Series | 96.7% |
| 13 | Citroen C4 (2020-present) | 96.2% |
| 14 | 2017-2024 Suzuki Swift | 95.7% |
| 15 | Ford Focus (2018-present) | 94.9% |
| 16 | Volkswagen Taigo (2021-present) | 94.7% |
| 17 | Seat Ateca (2016-present) | 94.4% |
| 18 | Audi A1 (2018-present) | 93.9% |
| 19 | Mazda CX-30 (2020-present) | 93.4% |
| 20 | Skoda Kamiq (2019-present) | 92.7% |
| 21 | 2017-2023 Ford Fiesta | 92.0% |
| 22 | Ford Puma (2019-present) | 92.0% |
| 23 | 2013-2020 Volkswagen Golf | 91.8% |
| 24 | Skoda Kodiaq (2016-present) | 91.8% |
| 25 | Mercedes A-Class (2018-present) | 91.6% |
| 26 | Mazda MX-5 (2015-present) | 91.5% |
| 27 | Dacia Sandero (2021-present) | 91.0% |
| 28 | Skoda Scala (2019-present) | 90.5% |
| 29 | Porsche 911 (2019-present) | 88.5% |
| 30 | Jaguar F-Type (2014-resent) | 88.3% |
| 31 | 2015-2024 Jaguar XE | 88.1% |
| 32 | Audi A4 (2015-present) | 86.6% |
| 33 | 2015-2024 Skoda Superb | 85.6% |
| 24 | Mazda 3 (2019-present) | 85.4% |
| 35 | Fiat 500 (2008-present) | 82.1% |
| 36 | MG ZS (2017-present) | 81.1% |
| 37 | 2014-2020 BMW 4 Series Coupe/Convertible | 79.0% |
How we compiled the survey
The latest What Car? Reliability Survey gained 29,967 responses and that enabled us to report on 199 models (up to five years old) from 31 different brands.
To compile the survey, conducted in association with MotorEasy, we ask thousands of car owners to tell us how well their cars had behaved over the previous 24 months.
For every car that has suffered a fault, we ask in what area the issue occurred, plus how much it cost to repair and how long it spent in the workshop. This information is used to create a reliability rating for each model and brand where we have a large enough response rate.
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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