Electric Vehicle Tyres

A few years ago, electric vehicles (EVs) were rarely seen on public roads, and people considered them more exotic curiosities than practical means of transport.

Nowadays, the situation has changed significantly and with their rise in popularity and improvements in technology, EVs feel the same as conventional cars day to day. But under the bonnet, they are like chalk and cheese, and additional considerations are also needed for the electric car’s tyres.

In this article, we’ll look closely at everything to do with your EV tyres, from learning how they differ from conventional tyres to why electric vehicles need specialised tyres. We’ll also answer the burning questions regarding EV tyre’s comfort, noise cancelling and traction capabilities.

How are EV Tyres different to regular car tyres

Despite their external similarities, internal combustion engine vehicles and electric vehicles require distinct tyre types. Manufacturers design the internal composition of the tyres to cater to the specific demands of two different kinds of vehicle.

The tyre-vehicle relationship is comparable to a runner's relationship with their running shoes. Specialised running shoes with customised support for your feet, weight, and running style, would improve your running power and efficiency; running in sandals would likely cause damage to both your feet and shoes.

Tyres, the shoes of a car, do the same thing. They improve the power and efficiency of your vehicle if chosen correctly.

EVs tyres have a higher load index.

EVs tend to be heavier than gasoline-powered vehicles due to the battery pack weight. For example, Ford's F-150 Lightning weighs 725kgs more than a conventional F-150. This additional weight increases the resistance on the vehicle and puts more stress on the tyres.

What's more, when an EV accelerates, you immediately use 100% of the vehicle's power, creating a sharper, more intense weight transfer. As such, tyres must fully withstand this power without slipping or pulling.

Similar to how runners require different shoes based on their weight and running style, EV tyres have a significantly higher load index than conventional tyres to compensate for the extra weight, especially when changing directions.

To do so, EV tyres have a reinforced, high-stiffness tread material with more than 30% higher wear resistance than the tyres of current internal combustion engines. They are also equipped with increased abrasion resistance technology.

During the manufacturing process, a number of different techniques can be used to achieve a lower rolling resistance, such as the rubber compound used in the sidewall rubber or inner liner, and applying rigid design patterns, tyre profiles and structures. Additionally, the high-stiffness material used to counteract the increased vehicle weight also helps optimise the tyre traction and reduce the rolling resistance.

Noise Reducing

EV powertrains are almost silent, so without engine sound, tyre friction noise that would be unnoticeable in a conventionally powered vehicle becomes significant at the same speed in an EV. Even the outside noise is louder. As such, manufacturers specifically design EV tyres with sound-absorbing materials giving you a smoother, more silent driving experience. The exact specifics of these techniques will be discussed in more depth later in this article.

EV tyres: traction and and braking data

As seen above, as electric vehicles have evolved, also have the tyres. The lack of internal combustion allows for instant acceleration but also puts additional strain on the tyres. What’s more, compared to combustion cars, EVs have lower emissions and running costs. However, the consequence of the battery pack that allows this is a significant increase in weight.

Luckily manufacturers haven’t needed to reinvent the wheel to solve these issues. Instead, they created tyres with reinforced, high-stiffness tread material to combat the increased rolling resistance; higher load index to counteract the excess weight; and installed sound-absorbing materials for a smoother, quieter ride.

The result?

Studies have shown EV tyres have different traction characteristics than traditional tyres, especially in wet or slippery conditions. For example, some research has found that EV tyres may have better grip and handling in wet conditions due to the lower centre of gravity and better weight distribution of EVs.

Overall, while more research is needed to understand EV tyres' traction performance fully, tyre manufacturers are working to develop tyres that provide optimal grip and handling for electric vehicles while balancing other vital factors such as energy efficiency and range.

Hankook, maker of the iON evo SUV has sponsored this explanation & overview of EV tyres & their unique challenges:

One of our leading choices for EV tyres would be the Hankook iON evo ASIH01.

EV tyres: comfort and and noise levels

Tyres are the only parts of a car that touch the ground. Therefore, it dramatically impacts ride comfort, handling, vibration, noise, and efficiency, which are essential elements of a vehicle's performance.

So, when it comes to electric vehicles (EVs), tyre manufacturers not only design EV tyres around performance parameters such as fuel efficiency, handling, and traction but on comfort and noise levels.

Reducing noise levels

One important aspect of the EV ownership experience is the serene in-car cabin experience. But, paradoxically, as EV powertrains are almost silent and without engine sound, tyre friction noise becomes significant in an EV.

To address this issue, tyre manufacturers began developing "Noise Reduction Tyres" designed to incorporate sound-absorbing materials giving you a smoother, more silent driving experience. The result is a noise reduction between 3db to 9db.

Several manufacturers of "Noise Reduction Tyres" implement sound-absorbing foam in the interior of their tyres to combat cavity noise. Each tyre manufacturer has their own marketing term and noise reduction claims, from Continental's ContiSilent to Pirelli's Noise Cancelling System. Still, they all work similarly.

After the tyre has been cured in its mold, a thick layer of polyurethane foam insulation is adhered to the inner liner of the tyre, either as a continuous piece or comprised of several shorter sections. The foam then blocks the vibration of the tyre from being transmitted through the wheel into the car's interior.

Improving the ride comfort

EV tyre manufacturers also focus on developing tyres to absorb road shocks and vibrations to provide a more comfortable ride. The previously mentioned polyurethane foam not only acts as a sound barrier for passengers but also reduces the vibrations coming from the road surface, increasing the perceived "smoothness" of the drive.

Another way tyre manufacturers improve ride comfort is by reducing tyre weight. Lighter tyres improve fuel efficiency and are easier to handle, but they can also be more comfortable to drive. Michelin has developed a new range of EV tyres called the "e-Primacy," which are up to 25% lighter than traditional tyres and can improve ride comfort and reduce road noise.

In addition to weight and construction, tyre manufacturers are exploring new tread designs that can provide better grip and handling while reducing noise levels. For example, Bridgestone has developed a unique tread design that combines 3D sipes and block edges to improve wet and dry grip while decreasing road noise.

EV tyres have a tricky brief. They must be strong yet lightweight, efficient yet affordable and, of course, long-lasting. Not to mention quiet and comfortable. The upside is that tyre manufacturers are taking a comprehensive approach to develop tyres for electric vehicles (EVs), focusing on meeting drivers' demands regarding performance, safety, comfort, and noise reduction.

As EV vehicles become increasingly popular, we can look forward to seeing continuous improvements in EV tyre technology, resulting in even more comfortable and quieter rides for EV drivers.

EV tyres: wear and and tear

Switching to an electric vehicle has a spectrum of benefits. In addition to being environmentally friendly, they reduce fuel expenses and eliminate some maintenance concerns.

However, as Hyundai found, generally, EV tyres wear out faster than regular tyres. Electric vehicles' tyres wear 20% faster than those of internal combustion engines due to the acceleration of electric cars that generate strong, instantaneous power and the significant weight of the vehicle's battery pack.

Battery pack weight

EVs tend to be heavier than gasoline-powered vehicles due to the battery pack weight. For example, Ford's F-150 Lightning weighs 725kgs more than a conventional F-150. This additional weight increases the resistance on the vehicle and puts more stress on the tyres.

EVs tend to have instant torque.

When an EV accelerates, you use 100% of the vehicle's power instantaneously. Even with electric cars with a low price point, you'll see them turn instantly at high speeds. There are no delays for driveshafts, gears or internal combustion engines to attain maximum torque.

The downside is that it creates a sharper, more intense weight transfer. As a result, this acceleration can cause more friction and stress on the tyres, particularly when starting from a standstill or making sudden stops.

However, while it's true that you'll likely have to replace your EV tyres more regularly, this is often mitigated by the maintenance upsides of EVs.

The reduced number of moving parts in electric cars translates to significant cost savings regarding general wear and tear. Maintenance tasks such as oil changes, drive belt and spark plug replacements, and gasket replacements are no longer necessary.

What's more, according to Napa, the lifespan of EV braking systems can be up to double that of traditional, gasoline-powered vehicles. This is because electric cars employ regenerative braking, which converts the vehicle's kinetic energy into a decelerating force. The car can then store this same energy for later use. Consequently, the brakes undergo less wear and tear, providing more stopping power.

When deciding whether an electric vehicle or EV tyres are right for you, it's essential to note negatives like wear and tear to other factors like driving habits, overall vehicle maintenance and fuel economy.