London - They are leading examples of upmarket ‘Chelsea Tractors’. And with classy looks, refined road manners and strong off-road credentials it's not surprising that they're sought after.

Yet four models in the Range Rover and Land Rover stables are among the most unreliable cars in the UK, a survey claims.

What Car? polled more than 18 000 car owners, who rated 159 models between one and four years old, documenting any problems they experienced over the past 12 months.

A perfect reliability rating of 100 percent meant drivers reported no problems.

The poll found the Range Rover was the second least reliable, with a rating of 67 percent. Non-engine electrics were the most common issue in these vehicles and 17 percent had suspension problems. Nearly a third of the cars had to be taken off the road for more than a week.

The smaller Range Rover Evoque was fourth least reliable, scoring 73 percent. Almost half of owners (45 percent) reported a mechanical fault over the past year. A faulty exhaust was the biggest issue. Next on the list were the Land Rover Discovery Sport with 75 percent and the Range Rover Sport with 76 percent.

The worst performer, with a reliability rating of 51 percent, was the Tesla Model S electric car. Faulty parking sensors were common here.

In joint top spot with 100 percent reliability were the Toyota Yaris and Suzuki SX4 S-Cross. They were followed by the Nissan Leaf, Toyota RAV4, BMW 3 Series and Honda Jazz petrol, on just under 100 percent.

The Peugeot 2008 crossover and Volvo V60 Estate scored 99 percent.