Does anyone have any numbers on the mpg of the smarty on fuel saver vs. smarty + comp if driven real soft?? Just wondering because i'd like to keep the power but fuel cost is getting crazy

 

Go down to 265 75 16's with highway tread pattern aired up to 80 in the front and 70 in the back. That should be good for 2 mpg.

 

You won't see much if any gain in mpg over 65psi up front. Same for the back tires at 55psi empty. If running loaded, take the rears all the way up to 80.

jmo

 

Hohn, what makes you say such things? Have you noticed no more increase above those levels of pressure? I know Semi's are different, but they run over 100 psi. I know it helps with the load, but it seems the harder the tire, the lower the rolling resistance.

 

It's diminishing returns. Every higher PSI is less of an increase than the one before it. In other words, going from 15-20 psi is a big increase, but going from 50-55 is a small increase.

In general, yes-- the harder the tire, the less the rolling resistance. But you reach a point where more pressure won't make a tire any harder.

It's that whole diminishing returns thing..

 

More air also makes the tire taller thus slightly changes the final drive ratio