What Car? Reliability Survey: Most and least reliable coupés, convertibles and sports cars

Coupés, convertibles and sports cars are cars you buy to enjoy, but getting one that's unreliable and costly to keep on the road could soon lead to misery. 

The good news is that most of the cars in this class are pretty robust, providing fault-free driving for most owners. The most common problems we were told about in the latest What Car? Reliability Survey are issues with the bodywork and various electrical systems. However, in many instances cars are fixed for free and they don't linger in the workshop for too long. 

This is why the class has a high average score of 93.8% for the past couple of years, which is better than all other car classes, aside from small cars, which are often simple and tend to have fewer sophisticated electronic systems to go wrong. 

Some sports cars, such as the Audi TT and Mazda MX-5, frequently appear at the top of the chart. It's not all about svelte coupés and roadsters, though, as some four-seaters, such as the latest BMW 4 Series Coupé and Toyota GR Yaris hot hatch, are also at the top of this category.  

For this story, we've pulled out all the data for coupés, convertibles and sports cars aged up to five years old. 

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Most reliable coupés, convertibles and sports cars

1. Toyota GR Yaris (2020-present)

Reliability rating 100%

• Most common faults: none

• Average repair cost: £0

• Typical time off road: n/a

This red-blooded, rally-bred hot hatch outperforms its more subdued, sensible namesake – the Yaris Hybrid small car – when it comes to reliability. In fact, not a single GR owner reported any faults whatsoever.

Not only did the GR Yaris post a 100% rating, but it’s also the only car in a class full of sporty models – including such pricey machinery as the Jaguar F-Type and Porsche 911 – to have achieved this feat in the past seven years of the What Car? Reliability Survey.

Owner’s view: “I appreciate the robust build quality and reliability of my car. I feel I can just drive it and not worry about it going wrong.”

Toyota GR Yaris review

2. BMW 4 Series Coupé / Convertible (2020-present)

Reliability rating 98.5%

• Most common faults: Non-engine electrics 6%, bodywork 2%, steering 2%

• Average repair cost: £0

• Typical time off road: 60% one day to a week, 40% one day or less

If you’re after a four-seat coupé or convertible that’s as dependable as it is classy, the 4 Series should be on your shopping list. Owners report few flaws and none had to contribute towards repairing unexpected faults.

Of the 8% of cars that owners said did go wrong, the bodywork and non-engine electrical systems were to blame, but these issues didn’t prevent any cars from being driven. Forty percent of defects were remedied in a day or less and the remaining 60% were sorted out in less than a week, with BMW covering all the costs.

BMW 4 Series Coupé review / BMW 4 Series Convertible review

3. Toyota GR86 (2022-present)

Reliability rating 97.9%

• Most common faults: 12-volt battery 5%, non-engine electrics 5%

• Average repair cost: £0

• Typical time off road: 100% more than a week

An old-school sports coupé, the GR86 is a rare thing in these times of electrification, so it’s good to know that this internal combustion-powered model is unlikely to let you down. If it does, you should have the reassurance that repairs won’t cost you anything; owners told us that Toyota paid for all fixes to their cars.

Only 5% of the GR86s in our survey had any glitches, and these all related to the 12-volt battery and non-engine electrics. It’s a shame, though, that all the faulty cars were walled up in the workshop for more than a week.

Toyota GR86 review

4. Mazda MX-5 (2015-present)

Reliability rating 97.5%

• Most common faults: Gearbox 7%

• Average repair cost: £0

• Typical time off road: 100% more than a week

The MX-5 is a great open-top option for anyone who wants a fun car that won't break the bank. It's affordable to buy and rarely goes wrong — only 7% of the cars we were told about had any flaws. Even better, Mazda covered the cost of putting things right for all those affected. 

The only concern is that all the cars that had issues with their gearboxes were rendered undriveable, and service departments took more than a week to fix them.  

Mazda MX-5 review

5. BMW i4 (2021-present) 

Reliability rating 96.8%

• Most common faults: Bodywork 5%, EV battery pack 3%, brakes 2%, motor 2%, non-motor electrics 5%, sat-nav/infotainment system 2%

• Average repair cost: 100% £0

• Typical time off road: 67% one day or less, 25% more than a week

The BMW i4 is essentially an all-electric version of the BMW 4 Series Gran Coupé – and that’s a good thing because the 4 Series and its close sibling, the BMW 3 Series, are pretty much the benchmarks in their respective classes. So it should come as no surprise that the i4 has brilliant performance, a plush interior and a good official range of 371 miles, as long as you go for the eDrive40, which has a larger battery than the eDrive35.  

While its fault rate is fairly high at 16%, most issues appear to be minor as 87% of the affected cars could still be driven. This is also reflected in the fact that two-thirds of issues were rectified in a day or less. It's also reassuring to see that BMW paid for all repair work. 

BMW i4 review

6. Audi TT (2014-2024)

Reliability rating 96.1%

• Most common faults: Air-con 4%, engine 4%, exhaust 4%

• Average repair cost: 80% £0, 20% £1-£50

• Typical time off road: 40% one day to a week, 40% more than a week, 20% one day or less

The Audi TT is an exceptionally good all-round coupé and convertible that offers lashings of driving pleasure combined with lots of everyday usability. It has agile handling, solid build quality and a healthy range of turbocharged engines. 

It was discontinued in 2024, and it's starting to show its age here with a fairly high fault rate of 20%. However, all the cars that went wrong could still be driven and most issues were sorted out for free. Getting things put right isn't that swift, though, with four out of five faulty cars out of action for more than a day and 40% in the workshop for more than a week. 

2014-2024 Audi TT review

7. Porsche 911 (2019-present) 

Reliability rating 94.8%

• Most common faults: Sat-nav/infotainment 18%, gearbox/clutch 6%

• Average repair cost: 60% cost £0, 40% cost £1-£50

• Typical time off road: 60% one day or less, 20% one day to a week, 20% more than a week

The Porsche 911 is a thrilling sports car and that's also surprisingly easy to live with. The entry-level Carrera is likely to be punchy enough for most people, although if you want a manual gearbox, you'll have to move up to the Carrera T. The Carrera GTS, meanwhile, has mild hybrid technology to boost its power. 

The 911 isn't perfect when it comes to reliability, though — 24% of the examples reported on went wrong, with the infotainment system and gearbox causing concern. That said, all affected cars remained driveable and nearly two-thirds were put right in a day or less. Porsche covered most repair costs, and where owners were asked to pay, the amounts were minimal. 

Porsche 911 review

8. BMW 2 Series coupé / convertible (2021-present)

Reliability rating 93.3%

• Most common faults: Bodywork 12%, non-engine electrics 8%, fuel system 4%, interior trim 4%

• Average repair cost: 100% £0

• Typical time off road: 55% one day or less, 27% up to a week, 18% more than a week

The 2 Series Coupé and Convertible is best thought of as a mini BMW 4 Series because it shares many of its oily bits with that car. This is a big departure from the previous generation 2 Series, which was essentially a 1 Series with a saloon-style boot. 

However, the 2 Series isn't proving quite as robust as the 4 Series, according to owners who told us 36% of their cars had gone wrong. Most issues were minor, though, with the most common complaint concerning the bodywork. BMW paid for all fixes, and more than half of the cars were in and out of the garage in a day or less.  

BMW 2 Series Coupé review / BMW 2 Series Convertible review

9. Mercedes CLA (2019-2025)

Reliability rating 92.7%

• Most common faults: Non-engine electrics 14%, 12-volt battery 10%, bodywork 5%, brakes 5%, fuel system 5%, sat-nav/infotainment system 5%

• Average repair cost: 100% £0

• Typical time off road: 56% one day to a week, 22% one day or less, 22% more than a week

The second-generation CLA is a great all-rounder, with an upmarket interior and good driving manners. It also looks like good value with the earliest examples priced from £16,000.  

Reliability is pretty good — although 19% of the cars in our survey went wrong, all of them could still be driven. Electrical issues and problems with the 12-volt battery were the most common issues. Although Mercedes was slow to sort out problems, it did cover the cost of all remedial work.  

Mercedes CLA review

Least reliable coupés, convertibles and sports cars

1. Porsche Taycan (2020-present)

Reliability rating 81.2%

• Most common faults: Bodywork 14%, 12-volt battery 7%, air-con 4%, brakes 4%, engine 4%, fuel system 4%, non-engine electrics 4%

• Average repair cost: 33% cost £0, 24% up to £750, 17% £1001-£1500, 8% more than £1500

• Typical time off road: 50% more than a week, 33% one day to a week

Porsche’s fully electric four-door coupé suffers from more problems than its less expensive BMW i4 rival (and that car’s non-electric 4 Series Coupé sibling). Taycan owners told us that 54% of their cars had gone wrong in some way, compared with 16% of i4s and 8% of 4 Series Coupés.

The Porsche’s main problem area was the air-con, which accounted for 22% of issues; EV batteries and 12-volt batteries also caused headaches for some owners. Repairs were slow, with 81% of cars taking more than a day to fix, but Porsche paid for virtually all of the work.

Owner’s view: “I’ve had issues with intermittent failure of the surround cameras and other digital gremlins.”

Porsche Taycan review

2. Jaguar F-Type (2013-2024) 

Reliability rating 81.9%

• Most common faults: 12-volt battery 20%, suspension 20%, sat-nav/infotainment system 13%, interior trim 7%

• Average repair cost: 73% cost £0, 27% cost £101-£350

• Typical time off road: 64% one day or less, 36% more than a week

Slow repairs and some high repair bills are the biggest concerns of F-Type owners. They told us that 71% of their faulty cars were off the road for more than a week, and only 29% were fixed in a day or less. While 86% of glitches were paid for by the car maker, the rest cost more than £1500 per fault to put right.

Overall, 27% of F-Types were afflicted by at least one fault, with engine-related electrics causing the most grief. This affected 13% of the defective cars, but owners also reported problems with the air-con, bodywork, exhaust and steering.

2013-2024 Jaguar F-Type review

3. Porsche Boxster / Cayman (2016-present)

Reliability rating 89.8%

• Most common faults: Non-engine electrics 9%, air-con 4%, engine electrics 4%, exhaust 4%, sat-nav/infotainment system 4%

• Average repair cost: 67% cost £0, 33% cost more than £1500

• Typical time off road: 33% one day or less, 67% more than a week

Porsche’s most affordable models aren’t the brand’s most dependable. A third of the Boxsters and Caymans reported on in our survey had at least one issue, and a number of areas were problematic, including the air-con, brakes, engine electrics and infotainment.

The good news is that Porsche took care of the repair bills for all affected cars. However, getting them fixed could be a slow process; 44% of faulty cars were in the workshop for more than a week, 33% took up to seven days to put right and only 11% were fixed in a day or less.

Porsche Boxster review / Porsche Cayman review

Reliability of coupés, convertibles and sports cars aged up to five years old

To read the reliability data for other car classes follow these links:

Most and least reliable cars overall 
Most reliable car brands 
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 diesel cars 
Most reliable petrol cars 
Most reliable hybrid cars 

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, and has focussed on consumer issues for much of that time. She was the advice columnist for Carweek magazine in the 1990s, helping car owners with faulty cars get the right level of reparation from car makers.

She also spent six years working on motoring content for Which?, and 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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