Just added Pirelli Scorpion ATR 275 55 20 to my truck and wanted to know the recommended PSI for these tires? Also if you have a Edge, what do have your tire size set at?
Got rid of the Toyo OC, they did not hold up for crap only about 20K miles. I wanted to get the BF KO's but would have run close to 2k, got the Pirellis for $700 plus a $100 rebate @ Discount Tire..Im happy
TIA for your help.

 

Anyone?

 

Did a search, help a brother out..

 

On the PSI, i'm running 40 and if my math is right with the formula Edge gave me the tire size is 2546.2668. I'm running 2546.3. But to me the speed is still off by 2-4mph. Hope this helps. I've had the factory rims and tires (Pirelli Scorpion ATR 275 55 20) for about a month. All and all they turned out to be pretty good. And with the Edge I could still spin them freely.

 

I'm running 40 psi in the front and 37 psi in the rear with empty load, 40 psi when loaded.

Don't bother using a "formula" to figure out your tire circumference because you will not be able to accurately take the tire "squish" into account. Instead, pick a spot on the road and mark it, roll the tire three times, and then measure the distance traveled. Divide that number by three, and you have yourself the tire circumference. I suggest using the rear tire as the guide, as that is where your speed sensor is (if I remember corectly).

 

Awesome Thank you guys

 

Why do it three times? Once will give you the same answer. .

The rear or front tires don't make a difference unless you're going to re-do it every time you rotate your tires.

 

3 will give you a slightly more accurate reading, because it is really hard to turn a 35"+ tire EXACTLY one revolution.. especially when you are measuring in mm's

 

I have the 20's and the door jam says 35 PSI front and rear, I have found if you stick to that you get a softer ride then the 40 PSI other suggest. When I tow my camper I max them out at 44 PSI front and rear and have towed over 2000 miles at that pressure with no ill effects on treadwear. Once I unhook from towing I lower them back to 35 PSI.

Since you are new to the 20's you will find that they do flat spot quite easy atleast mine do and will ride like they need balancing in a bad way but smooth out after a few miles of driving, that to is listed in the front of the owners manual.