Are electric vehicle (EV) tyres different from regular tyres? Can any tyre work for an EV? Many drivers may prioritize the cheapest option, disregarding the evidence that premium tyres outperform super-cheap unknown brands in terms of grip, handling, braking distance, comfort, noise, economy, wet performance, and wear rate.
However, fitting a tyre that is not specifically designed for an EV can lead to costly mistakes. So, why are tyres engineered differently for EVs compared to internal combustion engine (ICE) cars? There are four main reasons.
Firstly, EVs weigh significantly more due to battery weight. For example, the entry-level Volkswagen ID 3 weighs almost 30% more than the conventional Volkswagen Golf equivalent.
Additionally, torque plays a crucial role. Electric drive motors deliver high torque instantly, even in ordinary EVs, which can potentially result in increased tyre wear.
Noise is another important factor. The quiet drivetrain of an EV makes road and wind noise more noticeable, even during acceleration or cruising at high speeds.
Finally, there is the aspect of economy and rolling resistance. While rolling resistance affects both ICE cars and EVs, a 10% increase in rolling resistance during a 200-mile drive is more noticeable to an EV driver.
Tyre manufacturers address the added weight of EVs by enhancing the load-bearing capacity of the tyre carcass. This involves reinforcing sidewall construction and using tougher rubber materials.
In 2021, Continental introduced the first tyre with a load rating of HL (‘High Load’, with a load index of 825kg), while an ICE car of the same size may have a rating of SL (a load index of 94kg).
Continental also developed a new compound called Green Chili 2.0 for its EcoContact 6 tyre. This compound consumes less energy when deformed (while rolling) and reduces energy consumption by 15% compared to its predecessor. Other tyre manufacturers have also developed lower-rolling-resistance compounds.
The tread design, distribution on the road surface, internal belt design, and the bead that grips the wheel rim all impact rolling resistance. These factors are crucial considerations for engineers when developing tyres for heavier and torquey EVs.
Tread block widths are already varied randomly to minimize droning noise, and their design is now under increased scrutiny. Foam layers on the inside of the tread help absorb noise from vibration. Continental refers to its polyurethane foam as ContiSilent, which reduces road noise by 9dBA.