TESLA and Land Rover are the most unreliable motor cars on the British roads.

So say Which?, where Elon Musk’s pricey Tesla electric vehicles have disastrously-high fault rates and lengthy garage stays getting the poorest possible mark for 0-3 year reliability.

Their dependability was shocking for a car which sells from £76,990 and its Model X SUV costs from £81,990.

The Land Rover was the least dependable brand in two categories — cars aged up to three years, and three to eight years and electronic gadgets were often faulty — particularly in the Range Rover Sport (2013-) and the Range Rover Velar (2017-).

So many owners complained to Which? that it raised the issues with the manufacturer.

Land Rover was the only manufacturer out of the 35 in our survey to get one star out of five for both 0-3 and 3-8-year brand reliability. 

Why is Land Rover so unreliable? It’s easy to point the finger at diesel. Thanks to the survey, Which? know diesel cars are more fault-prone than others – particularly among older cars. Land Rover has historically been a diesel-heavy manufacturer. 

But Land Rover’s reliability goes beyond the fuel it’s burning. One of the most common issues across Land Rovers is nothing to do with its engines, but its digital gremlins. Owners bemoan problems with the car’s on-board computer software so often that we consider it a common issue across most of Land Rover’s SUVs. Two models in particular seem adversely prone to this issue: Land Rover’s current Range Rover Sport (2013-) and the Range Rover Velar (2017-). So many owners complained about the software that Which? recommended to Land Rover than it recalls these models and fix them for free.

The second-most commonly owned electric car brand in the Which? survey is Tesla and its reliability is shocking. Its seemingly desirable Tesla Model S saloon and Model X SUV both get the poorest possible mark for 0-3-year reliability thanks to disastrously high fault rates and lengthy garage stays. 

What is more concerning is the Tesla Model 3. Launched in 2019, it’s the most affordable Tesla to date and it’s popular. It was the third most-sold car in the UK during August 2019. 

Despite only being available for six months when the reliability survey opened, there were enough owners to rate it for reliability. 

Think a six-month-old car won’t have problems? Think again. Of the Tesla Model 3 owners Which? heard from, 26% had at least one problem that had to be fixed by a mechanic since taking ownership of their car. 

Admittedly, the faults tended to be minor, but it belies a general low level of quality: paintwork and other exterior trim problems were common, which is unusual. 

Although not overly frequent, a number of owners also reported problems with the car’s rainwater seals. The last thing you expect from your fancy new electric car is for it to let in water. Then factor in that three per cent of owners Which? heard from had already seen their car break down. The Model 3 looks destined to go the way of the Model S and Model X in terms of dependability. 

Which? have reliability ratings for 280 cars. You can see how reliable, or not, each model is in our independent new and used car reviews.

The survey also found that diesel cars are more fault-prone than petrol, hybrid and electrics.