Electric cars heavier on tyres than ICE equivalents

There is now a wealth of empirical evidence that electric cars are heavier on tyre usage than ICE equivalents due to the extra weight, a factor that fleet buyers need to take into account when assessing SMR budgets.

Compared to internal combustion cars, electric vehicles have lower engine noise, reduced emissions, and better maintenance and running costs. However, one consequence of switching to an EV is a significant increase in weight as batteries are heavy and their weight places additional strain on electric car tyres.

Electric cars accelerate quicker than petrol or diesel models but this instant acceleration puts additional strain on tyres - so the advice is to accelerate gently and to avoid hard cornering to limit wear and tear damage.

As tyres for electric vehicles carry a heavier load and have to withstand high instant torque, so tyres with stronger construction and more robust rubber compounds are required, especially as longer braking distances are typically involved.

To increase EV tyre longevity, maintenance is especially important.  As with other tyres, check the pressure regularly and adjust if necessary. Correct wheel alignment will reduce tyre wear and should be checked every six months, or sooner if the driver has hit a curb, pothole or other obstacle.

If possible, tyres should be replaced with original equipment models, which were not only designed for the needs of electric vehicles, but specifically made to fit the precise model being driven.  

TyreSafe, the UK charity dedicated to raising awareness of the importance of correct tyre maintenance and the dangers of defective and illegal tyres, says the technology behind tyres optimised for use on EVs is still evolving and enhancements over the coming years should be expected as the vehicles develop.

Owners of EVs should be aware these tyres have characteristics which separate them from ICE models, says Tyresafe. As such, when they are replaced, TyreSafe recommends like-for-like replacement of EV tyres for reasons of safety, but also to ensure that the criteria of performance are best suited to minimise long-term costs.

To stop tyres distorting due to the extra weight, some tyres for EVs feature a ‘reinforced sidewall’ and may operate at higher pressures than for non-EVs. By reinforcing the sidewall, the tyre will more readily keep its shape and stiffness if it is kept at the correct pressure.

That means owners of electric vehicles need to be aware of the importance of correctly selecting a tyre and need to pay close attention markings on their tyres beyond simply their size., says Tyresafe.

Tyres fitted to EVs which have not been specifically designed for the purpose are likely to wear quickly and detrimentally affect the experience these cars can offer.

A longer-term consideration is how tyres will adapt to the arrival in the marketplace of vehicles conceived and designed from the very beginning as EVs rather than being adaptations of their petrol or diesel equivalents.

At present, the size of an EV wheel and tyre size is determined by the size of the brake package and how large the petrol or diesel vehicle equivalent’s wheel arch is. In future, TyreSafe expects designers to prioritise what an electric vehicle needs from the space allowed for its wheels and tyres. When that shift in a vehicle’s design happens, we should expect a wheel and tyre combination which is larger than the ones we commonly see today, while it is also very likely to be narrower, says Tyresafe.

Tyre manufacturers have been bringing out special tyres specially for EVs to tackle the issues of longer braking distances, due to the extra weight, and the additional grip required for some time.

Continental, for example, has developed its EcoContact™ 6, which, it says, relies on its premium Green Chilli 2.0 compound with grip additives for improved braking performance.

This has been developed to address the specific issues raised by the increased weight of EVs and hybrids and to balance the need for low rolling resistance, high grip and sturdiness.

However, Continental also opines that its other premium tyre lines with their ‘state-of-the-art tyre technologies’ already meet the requirements that arise for today's electric vehicles.

With increased weight from an electric vehicle, tread depth can decrease at a faster rate than on diesel and petrol vehicles. 

As a result, Goodyear says it has designed a tyre with an innovative tread design to avoid this. The tyre has smaller tread channels so there is increased rubber coming in contact with the road. This means the tyre can cope better with high levels of torque whilst still maintaining high performance in wet conditions.

At the end of last year, the company announced the launch of a new tire, new ElectricDrive GT, in the US designed to be optimized for electric cars, in a size compatible with the Tesla Model Y and Model 3, the two most popular electric cars in the US.

Goodyear has also announced it is partnering with Citroen to mark the vehicle manufacturer’s centenary with the production of  the C100 concept tyre  which is fitted to Citroën's autonomous, connected, electric vehicle 19_19 Concept.

The C100 concept tyre boasts a tall and narrow structure almost one metre in diameter versus 60cm for regular tyres for energy efficiency and to improve range. The C100’s tread groove compound is said to be inspired by the attributes of a natural sponge it stiffens  in the dry or softens in the wet.