2021 What Car? Reliability Survey: luxury cars

We reveal the most – and least – dependable cars up to five years old, based on the experiences of more than 16,000 owners...

BMW 5 Series

Most reliable luxury cars

1. BMW 5 Series petrol (2017-present)

Reliability rating 96.9%

What went wrong? Non-engine electrics 8%, brakes 4%, engine 4%

Petrol 5 Series models suffered almost half the number of faults as diesels, with 16% going wrong compared with 31% of diesels. BMW covered the cost of all repairs, with 50% of work done in a day or less. Only 25% of cars spent more than a week in the garage.

Owner’s view “My car feels very well built and has been utterly reliable. It is, without exception, the best car I’ve bought”


2. Volvo S90/V90 (2016-present)

Volvo S90 long-term test review

Reliability rating 92.6%

Although 24% of S90s had a problem, most were minor issues with the bodywork, non-engine electrics and sat-nav. All cars could still be driven and 76% of faults were rectified in less than a week, with 56% taking a day or less. Eighty-four percent of work was done for free and no bills exceeded £750.

3. Mercedes E-Class (2016-present)

Mercedes E-Class 2021 front

Reliability rating 90.7%

Of the 21% of E-Classes with problems, battery, non-engine electrics and sat-nav issues were the main bugbears. All could still be driven, though, and nearly half were repaired in less than a week. While 74% of repairs were free, some owners faced bills ranging from £201 to £750.

Least reliable luxury cars

1. Audi A6 (2011-2018)

Used Audi A6 Avant

Reliability rating 82.1%

What went wrong? Battery 15%, bodywork 10%, brakes 10%, non-engine electrics 10%

The previous-generation A6 isn’t ageing well. Forty percent of the examples owners told us about had gone wrong, and only 60% of the faults reported were fixed for free, leaving many owners with repair bills, ranging from £101 to £750. The only good news is that half of the faults were fixed in a day or less.

Owner’s view “My car has had frequent problems with its digital dashboard and infotainment screen, as well as ‘false’ warning lights frequently popping up on the dash”

2. Audi A6 (2018-present)

Audi A6 40 TDI front

Reliability rating 85.3%

The current A6 had even more faults (47%) than the previous model, but most cars could still be driven and 93% of repairs were covered by Audi free of charge. No owners paid more than £300. Bodywork, engine and non-engine electrics, sat-nav and suspension issues were the main concerns.

3. BMW 5 Series diesel (2017-present)

BMW 5 Series cornering front three quarters

Reliability rating 89.1%

As well as suffering similar faults to petrol models, diesels also had problems with their bodywork, engine and non- engine electrics and exhausts. While 73% were fixed for free, many owners paid between £101 and £300, and 3% coughed up more than £1500. Better is that 73% of cars were fixed within a week.

Reliability of luxury cars aged up to five years old

Rank Make and model Score
1. BMW 5 Series petrol 2017-present 96.9%
2. Volvo S90 / V90 2016-present 92.6%
3. Mercedes E-Class 2016-present 90.7%
4. Jaguar XF 2015-present 89.6%
5. BMW 5 Series diesel 2017-present 89.1%
6. Audi A6 2018-present 85.3%
7. Audi A6 2011-2018 82.1%