How does wheel radius effect fuel efficiency?

Question

Do small wheels on cars translate to a great fuel efficiency? or do larger ones? Or does it have no effect?

Why?

It seems there is disagreement on this one.....

Answer 1

The larger the wheel radius, the farther the vehicle will travel down the road with every revolution of the engine, so it would seem that a larger radius wheel would be more efficient.

However, all cars are designed for certain size tires and wheels, and the modern day suspension systems are more negatively responsive to making changes, so I would not start substituting other than recommended size tires and wheels on a vehicle before checking with a mechanic or someone who is familiar with what effect it will have on the suspension and other systems.

Answer 2

Speaking in terms of wheels, definitely wheels having greater friction with road will increase the amount of fuel your car consumes.

I think it doesnt depend on how large or small your wheel is. It depends on how much pressure of air is in the wheels. Greater pressure will cause the wheel to stay inflated and consequently less surface area of wheel will be in contact with the road which means less friction and therefore less fuel consumption.

Likewise less air pressure means greater friction and greater fuel consumption.

But air pressure is kept at a certain pressure (neither too high or too low) since high air pressure in wheels will cause a bumpy ride.

Answer 3

In general, smaller wheels will experience greater rolling friction due to vertical irregularities in road surface. With pneumatic tires the effect is small.

Answer 4

FUEL EFFICIENCY HAS NOTHING TO DO WITH WHEEL RADIUS. FUEL EFFICIENCY IS FUNCTION OF ENGINE THERMODYNAMIC CYCLE, COMBUSTION EFFICIENCY, SPEED OF CAR , AND LOAD . Wheel size is governed by stability considerations .