KATHMANDU: Electric cars remain roadworthy for longer than petrol cars, with the reliability gap becoming wider as mileage increases, according to a large-scale study in the United Kingdom.
The study analyzed data from millions of annual MOT tests, the UK’s standard vehicle roadworthiness test. The tests cover areas including suspension, brakes, tires, exhaust and emissions.
Researchers compared how likely petrol and electric cars were to return for another MOT test. In the early years, there was little difference between the two powertrains. EVs initially showed slightly more issues, which researchers linked partly to EV owners driving more miles during the early years of ownership.
However, the difference became clearer after vehicles crossed 40,000 miles. Petrol cars became less reliable as mileage increased, while EVs continued to perform better.
At 120,000 miles, petrol cars were found to be 7.5 percent more likely to have failed compared to electric cars. The failure rate stood at 23.5 percent for petrol cars, compared with 16 percent for EVs.
The study also found that EVs remained more reliable as they aged, despite generally being driven more each year than petrol cars.
Researchers also compared models available with both electric and petrol powertrains. Except for the Volkswagen Golf, the electric versions either matched or outperformed their petrol counterparts in reliability.
Many of these EVs were based on platforms originally designed for petrol-powered cars rather than dedicated electric platforms. Their additional weight resulted in higher tire wear compared with petrol versions.
However, dedicated EVs such as the BMW i3 recorded lower tire wear than converted models such as the Volkswagen Golf. The additional weight of EVs did not result in more suspension problems, with electric cars showing fewer suspension-related issues than petrol cars across different mileage levels.
EVs also recorded fewer brake-related problems, largely due to the use of regenerative braking. However, electric cars more than 10 years old showed a higher rate of brake problems than petrol cars. Researchers linked this to underuse and corrosion caused by reduced reliance on conventional brakes.
The findings suggest EV owners should occasionally use the conventional brakes and regularly check tire condition.
The study also included light commercial vehicles. Electric versions, such as the Nissan NV200, generally outperformed their diesel counterparts across most categories, although tire wear remained an issue.
The study did not assess battery health because battery condition is not part of the MOT test. However, separate large-scale battery research has found that EV batteries can retain around 90 percent of their original capacity even after 90,000 miles of use.
