The most common cars vulnerable to faults

The more tech and electronics there are in a car, the greater the chance that the car will experience a fault. Read our blog on reliability issues in used cars for more on faults.

The race is on for manufacturers to cram as many technological advances into new vehicles as possible: which is causing something of a headache for new owners.

Audio/communication/entertainment/navigation (ACEN) systems account for half of the 10 most problematic issues that owners cite with their new vehicle. These faults are cascading down into the used car market. What’s true for new cars is also true for used.

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JD Power PP100

A trusted measure of the vehicle reliability comes from consumer analyst JD Power. It’s annual study, which is now in its fifth year in the UK, measures the number of problems experienced per 100 vehicles (PP100). The lower the score, the better the performance.

The study measures 177 problem symptoms in eight categories: vehicle exterior; driving experience; features/controls/displays (FCD); audio/communication/entertainment/navigation (ACEN); seats; heating, ventilation and air conditioning (HVAC); vehicle interior; and engine and transmission.

The 2019 UK Vehicle Dependability Study is based on responses from 11,530 owners of new vehicles registered from November 2015 to January 2018. The study, which measures problems experienced during the past 12 months by original owners of vehicles in the UK after 12-36 months of ownership, was fielded from November 2018 to January 2019.


Engine failure

Engine problems have the greatest negative effect on quality and reliability scores across the industry, as well as among premium brands. In particular, owners of premium vehicles are 12% less likely to repurchase the same brand when an engine problem occurs.

Technology issues

According to JD Power, as technology becomes more sophisticated—and is considered a point of brand selection differentiation—brands are creating more potential problem areas for themselves.

For instance, the average score for newer safety technology features such as blind spot monitoring, collision avoidance and lane departure warning systems is 2.4 PP100. This climbs to 4 PP100 for premium brands. Other features, controls and display systems, including alarms, keyless entry and cruise control, proved less vulnerable to faults.


Among premium brands Volvo ranks the highest, followed by Mercedes-Benz. Other premium brands, however, don’t fare so well in the study.

The 7 most common premium car brands vulnerable to faults, from worst to best, are:

  1. BMW: Common problems depend on age and model. Typical faults include door locks, rattling, electrical problems and check engine light illumination, which could be minor, or something catastrophic.
  2. Fiat: Most reported problems include steering, brakes and exhaust.
  3. Audi: Oil and exhaust leaks, engine rattles, the engine warning light, and smelly heating and ventilation systems are all common faults across Audi’s range.
  4. Jaguar: Jaguar vehicles often have issues with the suspension, windscreen wiper failure and water leaks.
  5. Land Rover: The most common problems found in Land Rovers usually concern air suspension, oil leaks and sunroof leaks.
  6. Mercedes-Benz: Rust, engine mounts, suspension and steering components, window regulators, catalytic convertors and the check engine light are all possible problem areas on Mercedes-Benz models.
  7. Volvo: General problems with Volvo can emerge from the gearbox, injectors on diesel models and software upgrades. As mentioned earlier, tech safety features such as lane departure warnings and emergency stop systems are prone to failure, causing a headache for owners.


See our list of the most reliable cars.

To make sure you are getting the most reliable premium used car possible have a look at our used car guide. Then visit to see our latest range of prestige used cars.