EV Advice: Changing tires and battery range

The arrival of spring in Canada means the removal of winter tires for many drivers, including EV owners. And changing those softer and generally stickier winter tires to all-season tires featuring lower resistance that sometimes come with plug-in vehicles (or are purchased for them) means owners will usually see an increase in their driving range.

Exactly how much is difficult to calculate, because tires are only one of the factors – others include warmer temperatures and a reduced need to heat the interior of the vehicle – that helps improve range.

The U.S. Department of Energy (DOE) has reported that gas-powered vehicles generally use four to 11 per cent of their fuel just to overcome rolling resistance. And, in more efficient all-electric EVs, the figure cited is 25 per cent. Low rolling resistance (LRR) tires still create drag, especially on the highway, but the DOE reported that a 10 per cent reduction in rolling resistance leads to a roughly three per cent decrease in fuel consumption. If the same ratio of improvement applies to EVs, these numbers suggest there are worthwhile range benefits to choosing LRR tires.

For us, we tried all-weather tires on our Ford C-Max PHEV a few years back, specifically Kuhmo Solus HA31s, which have the snowflake symbol stamped on them. We found them great in the first winter, and super convenient for avoiding tire swaps twice a year, but far from great during the second winter.

Admittedly, we hadn’t rotated them in those two years – we were used to rotating when the winter tires came off and on – so they had travelled roughly 25,000 kilometres at that point.

We were happy to find ourselves back on true winter tires the past two seasons, on Michelin X-Ice Xi3s, and found that purchasing a separate set of wheels is more costly up front but will save you money over the life of the tires. And we honestly didn’t notice much of an EV range difference with either tire.

There are now a new generation of EV-specific tires, such as Goodyear’s new ElectricDrive GT and the Michelin Pilot Sport EV, which have stiffer sidewalls to better support the weight of heavier EVs, lower rolling resistance and feature special sound-deadening.

We haven’t sampled any of these yet, but for now, we’re looking forward to the annual bump in temperatures that comes in spring, and the increase in our vehicle range, no matter what the precise reason is.

Michael Bettencourt bought his first EV in late 2011 and has followed the Canadian EV scene ever since. Follow him on Twitter @MCBet10court