Forbes: Carbon fibre wheels could be next boost for EV range

7 July, 2022

As the global EV rollout gathers pace manufacturers are seeking to reduce vehicle energy consumption. Given the cost and mass of batteries, improving efficiency is critical for EVs to get the most range from the least amount of battery, Forbes writes.

Use of carbon fibre to improve EV efficiency dates back to 2013, when BMW employed the lightweight material in the i3. However, the approach being pitched by Carbon Revolution with a focus on the wheels may turn out to be both more cost effective and offer a greater efficiency advantage.

Not all mass reductions have the same impact

Weighing 40% less than a similarly sized alloy wheel, carbon fibre wheels are significantly lighter – but in the case of a wheel, this lighter mass reduces vertical, horizontal and rotational inertia.

The result: not only do lighter wheels save weight, but they also require less energy to accelerate, brake and steer, all of which means more range in an EV (and better ICE fuel economy).

As automakers respond to market demand for larger wheels, the mass and inertia reductions associated with carbon fibre become more profound – up to 60kg (130 lbs) can be saved on a typical SUV, paying significant range dividends.

Further range improvements come from aerodynamics – carbon fibre wheels offer the ability to incorporate thin structures into the wheel without weight penalty, reducing drag in an area which plays a significant role in a vehicle’s overall aerodynamic efficiency.

Shelby GT500 Mustang aerodynamics

Wheels play a significant role in vehicle’s aerodynamic properties. Source: Ford

Reducing road noise in silent vehicles

The silent powertrain of an EV makes all other noises in the vehicle more obvious. To reduce the in-vehicle noise, many OEMs are adding mass to already heavy EVs in the form of mass dampers or stiffer and heavier components, or in the form of sound deadening material.

Carbon fibre offers an obvious advantage here: not only is it a high stiffness-to-mass ratio material, but the material itself is also well damped and does not transmit noise as easy as a metallic structure.

What’s more, carbon fibre’s anisotropic nature allows Carbon Revolution engineers to modify the wheel’s complex internal structure, and effectively ‘tune out’ road noise. The result is up to 5 dB less road noise coming into the cabin, without any additional material required.

Expanding the factory for the EV revolution

Carbon Revolution recognises the improved efficiency and desirable attributes in styling, noise and aerodynamics are desirable among automakers.

Already a supplier to Ford, Ferrari and General Motors, the company is scaling up and further automating its factory to bring new OEM programs on-line, many of which will be for EVs.

Read the full story in Forbes

*Please note, the original article incorrectly quotes a projected production figure for 2022. Carbon Revolution does not project annual production figures. However in March 2022 the company celebrated the milestone of 50,000 wheels sold to-date.