A vehicle is being driven with low tyre pressure. How much fuel will it use?

Correct answer

More than with normal pressure.

A vehicle being driven with low tyre pressure will use more fuel than if the tyres had normal pressure. This is because underinflated tyres cause a number of problems that increase rolling resistance and reduce the vehicle's efficiency. These problems include: Sidewall deformation: tyre sidewalls deform more when the pressure is insufficient, causing an increase in rolling resistance. Uneven wear: tyres with low pressure tend to wear unevenly, especially at the edges of the tread, which shortens their working life. Blow-out risk: low pressure increases the risk of a tyre blow-out, which can result in dangerous accidents. Reduced grip: underinflated tyres offer less grip on the road, which is especially dangerous on slippery or wet surfaces. Increased fuel consumption: the extra rolling resistance caused by underinflated tyres means the engine has to work harder to move the vehicle, resulting in higher fuel consumption.