A recurring call regarding road safety is to have good tires on the car, as they are the only thing that actually has contact with the road surface.
Modern cars are constantly getting smarter through various assistance systems and digital aids that should help minimize the human factor.
However, if you choose to drive around on bad tires, none of the safety features mentioned above matter much. The risk of accidents increases significantly.
The track for electric cars
The tire manufacturer Michelin invited to the Gotland Ring motorway, which is located in the northern part of Gotland.
It is a race track that is classified as the world’s longest by modern standards with a length of 7.3 kilometers.
Gotland Ring is to be the world’s first sustainable racing track. Photo: William Koitrand
Gotland Ring also prides itself on being the world’s first sustainable race track. The track and buildings are built with recycled materials, and all electricity consumed comes from the surrounding wind turbines and solar power.
The electricity goes, among other things, to a couple of fast chargers that are right next to the track for those who want to push their electrified cars for a few laps.
A sustainable transition
The transition to electric operation affects not only car manufacturers, but also the tire industry.
Michelin naturally wants to keep up with the changes and therefore puts a lot of focus on adapting the tire range for electric vehicles and modern sustainability requirements.
The weight of electric cars is a challenge in tire development. Photo: William Koitrand
Here, a balance is required between rolling resistance and safety, while the noise level from the tires is also more important than ever given the otherwise quiet progress of electric cars.
The impact of electric cars is significant
Electric cars generally have much higher torque than corresponding petrol and diesel cars, and the torque is also delivered directly, which results in increased tire wear.
The large batteries that power electric cars generally have a higher curb weight than the equivalent in combustion cars, which also accelerates wear and tear.
Michelin’s own tests show that electric cars wear out their tires about 20 percent faster than cars with a combustion engine.
Two selected summer tires
During our stay at the Gotland Ring, we had the opportunity to examine two different summer tires, the Michelin e-Primacy and the Michelin Pilot Sport EV.
The e-Primacy tire has been developed with a focus on lowering the rolling resistance as much as possible and at the same time maintaining a long service life.
The Pilot Sport EV is more focused on performance where the tire should provide better grip, while maximizing range and being as quiet as possible. This has been a major challenge according to Michelin.
An enthusiastic owner
To demonstrate exactly how Michelin tires perform in terms of rolling resistance, braking properties and driving characteristics on electric cars, we had to try a number of test moments.
When we arrived at Gotland Ring, we were met by the Finnish-Swedish owner Alec Arho-Havrén, who enthusiastically told us about the sustainability work around the track and its past as a limestone quarry.
The wind turbines around the track supply the electric cars with power. Photo: William Koitrand
After the briefing, we had the opportunity to ride in two different Porsche Taycans with Alec behind the wheel (LINK). One car was equipped with Pilot Sport 4S and the other with Pilot Sport 4.
The sky shone gray but the lack of precipitation meant a dry track that invited some really dynamic driving on the two performance tyres.
Full roll around the track
With Alec behind the wheel, it was full roll around the track. He showed that it is possible to keep the gas at the bottom in places where less experienced drivers would have undoubtedly chosen to let off the pedal.
After riding in both cars on different tires, we were able to state that the performance tire Pilot Sport 4S is the one that is perceived as the fastest and has the most grip in the curves.
The Pilot Sport 4 is also a competent tire, but it allows a little more slack, which enables a livelier driving style where driving pleasure is prioritized over record-fast lap times.
Shortest braking distance on wet ground
During the day, we also got to participate in three other exercises where Michelin put its own tires to the test against a competitor.
The first activity involved hard braking on wet surfaces. The cars were a bunch of Volvo XC40 Recharge, with which the Michelin Sport EV tire was put to the test against the Pirelli P Zero.
A test of braking distance on wet surfaces was on the program. Photo: William Koitrand
During the actual braking, no major difference was noticed between the tires, but the result was clear. During the day, the Michelin tire had an average braking distance of 23.7 metres, while the Pirelli qualified at an average of 24.7 metres.
Who has the lowest rolling resistance?
The second activity was a visual demonstration of rolling resistance where two A-rated tires were pitted against each other.
Michelin’s e-Primacy beat the competitor Continental EcoContact 6 time and time again, indicating that Michelin’s work for minimal rolling resistance and maximum range has paid off.
Driving on dry became wet
Phase three consisted of a test of noise level and driving experience.
The event was supposed to be held on a dry surface but the aforementioned gray skies had opened, and the rain had quickly soaked the previously dry surface.
The writer listens to the tire noise in the Polestar 2. Photo: William Koitrand
We rotated between a bunch of identical Polestar 2s to feel the difference between the e-Primacy and the Pilot Sport EV.
Both tires performed well but the pace around the track was calm and the heavy rain made it difficult to compare noise levels.
Relevant for all cars
Michelin is clear that all their tires are compatible with electric cars, but that some tires are categorized as electric car compatible.
It is likely that the classification will disappear over time, as even a conventional combustion car obviously benefits from low rolling resistance, long service life and low tire noise.
Michelin’s Swedish CEO, Marika Hoflund, said that the tire manufacturer takes sustainability work very seriously, where the biggest challenge is to extend the life cycle of the tires.
Hoflund believes that a premium tire can be worn down to the legal limit of 1.6 millimeter tread depth without jeopardizing road safety.
Michelin’s long experience seems to be paying dividends now that electric cars are raising the demands on the tire’s combination of longevity, safety and rolling resistance.