Any problems running 45 PSI on the jeep with pro comp xtreme a/t 305/65/17 and stock suspension?

I had been running them at 35 psi as set by the shop and notice my combined mileage went from 17 to 15. I aired them up to 45 psi today after reading some folks ran them that high and noticed an improvement in driving right away. The jeep seems to accelerate easier and coasts much further when I take my foot off the gas. I reset the meter and got 16+ in the city, so think my combined driving will probably get back up to 17 or better.

 

Filled that high, you are running on just the very center of the tread. Decide if the mpg savings offsets the cost of the new set of tires when those wear out prematurely.

 

Try doubling the pressure, 90psi and see if you can get 32mpg.

 

I'm running 36psi up from 32. I definitely noticed it was a little bit stiffer let us know how it goes.

 

I'm thinking more like 35 mpg.

 

You can back off the accelerator after every bounce - that should increase mileage.

 

Ok, 45 may have been over the top. Very bouncy and highway mileage didn't improve much, but I do have the top off and usually drive with windows down so not much help aerodynamically. Dropped it down to 40psi. Drives a little better, but still a bit bouncy so will try 38psi next.

 

 

have you done a chalk test to see how much of your tread is actually making contact with the ground? sure, less foot print will offer less rolling resistance but, as mentioned, you're just causing your tires to wear out prematurely down the middle.

 

I usually run mine at 40psi on the road in my stock 2-door 6 speed. Recently, after a day of wheeling I only aired them back up to 35psi as I couldn't be bothered waiting for my slow ass compressor to do it's job. On the 100-odd mile trip back home the difference was very noticeable. The ride was certainly a bit softer & less bouncy, but I found I was downchanging more frequently on hills and to overtake and having to use more gas pedal just to maintain speed on the flat, let alone on hills. I calculated a loss of about 4-5 MPG running 35psi at 70MPH over 40psi at the same speed.

So higher psi's certainly make a noticeable difference to performance and mileage. At 40psi my tires always wear evenly and that's on a light stock 2-door, so 45 shouldn't affect the wear pattern too much though the ride may be as bouncy as all hell compared to what you're used to on 35psi.