Help. Taller tires=lower rpms, but also lower mpg??

[styng88]

This has always boggled my mind. If you're turning less rpms, shouldn't you be getting better fuel economy? How much extra power would be needed to turn a taller tire? I'm running a 225-75, which is minimally taller.

 

[tymewarp]

If your tires are larger in diameter, then your odometer will also be registering less miles than you are actually traveling. You could still be using the same amount of fuel but it would appear that your mpg was lower if the odometer is incorrect due to the increase in diameter of the tires.

 

[JeepJeepster]

it takes more power to turn bigger tires, more gas. its like having a load on the jeep, like a boat or something.