Electric Vehicles Show Higher Tyre Defect Rates Than Petrol Cars, Study Finds

Electric vehicles (EVs) are nearly twice as likely to experience tyre defects compared to their petrol counterparts, according to new research analyzing over 47 million MOT tests in Britain.

The study, commissioned by the British Vehicle Rental and Leasing Association (BVRLA), suggests that the increased weight from EV batteries and the instant torque delivered by electric motors place a greater strain on tyres, potentially leading to higher wear and defect rates. Some EV owners may be facing a 'tyre tax' due to these increased repair costs, with premium tyre replacements costing hundreds of pounds.

EV batteries can weigh between 660 and 1,100 pounds (300–500kg), making up as much as 25% of a vehicle's total weight. Unlike petrol engines that build power gradually, electric motors deliver maximum torque almost instantly upon acceleration, exerting more force on the tyres from the outset.

Analysis indicated that for electric vehicles with 20,000 to 40,000 miles, the rate of tyre defects per 100 cars was 5.8, significantly higher than the 3.2 rate for petrol cars. This disparity persisted with increased mileage, with cars showing 90,000 miles having a defect rate of 9.4 for EVs compared to 5.4 for petrol models.

Specific models showed notable differences. The Nissan e-NV200 experienced nearly seven extra tyre defects per 100 cars compared to its diesel equivalent. The VW e-Golf had almost five more defects than its petrol version, and the Hyundai Kona Electric had four additional defects.

However, newer EV models such as the BMW i3, Kia Niro EV, and Hyundai Ioniq Electric demonstrated better performance. These models are designed to distribute the heavy battery weight more evenly, which helps to reduce tyre wear.

The BVRLA recommends that fleet operators implement active tyre-pressure monitoring systems and specify EV-grade reinforced tyres for commercial vehicles.

Despite the higher tyre defect rates, EVs generally performed better in other areas during MOT tests. Between 90,000 and 120,000 miles, 16.5% of electric cars failed their MOT, compared to 22% of petrol cars of similar age and mileage.

Furthermore, modern EVs were found to be less prone to suspension and brake defects. As they do not have exhaust systems, this potential point of failure is eliminated.

The research challenges the conventional assumption that higher mileage inevitably correlates with increased mechanical risk. Toby Poston, chief executive of the BVRLA, noted that mileage is a primary factor for used car buyers, and passing certain mileage thresholds can negatively impact a vehicle's perception. He stated that this research suggests a need to re-evaluate perceptions of electric vehicles, particularly those entering the used market after fleet service with substantial mileage. "What this data shows is that mileage alone should not put consumers off," Poston said. "A well-maintained, higher-mileage electric car can be an extremely durable used vehicle."

This analysis was conducted by New AutoMotive, an organization advocating for the adoption of electric cars, and is believed to be the first large-scale examination of MOT data concerning EV tyre defects. Steve Walker, head of digital content at Auto Express, commented that the study primarily focused on older EVs and did not account for tyre types. He suggested that advancements in EV design and specialized tyre technology may lead to improvements in newer electric cars when they reach their first MOTs.