Red Seal Automotive Service Technician Practice Exam

How does low tire pressure affect fuel efficiency?

1. It improves it by enhancing grip

2. It has no impact on fuel efficiency

3. It reduces fuel efficiency

4. It increases it by reducing drag

The correct answer is: It reduces fuel efficiency

Low tire pressure reduces fuel efficiency primarily because under-inflated tires create more rolling resistance. When tires are not properly inflated, they deform more than they should when in contact with the road, leading to greater resistance and requiring more energy (in the form of fuel) to keep the vehicle moving. This increased rolling resistance means the engine has to work harder, which consumes more fuel and ultimately decreases efficiency. In addition to the rolling resistance, low tire pressure can lead to increased tire wear and potential safety issues, further impacting the overall performance of the vehicle. Maintaining the recommended tire pressure is essential for achieving optimal fuel efficiency and maximizing the lifespan of the tires.