Hey guys, just put on some Toyo Open Country ATII 33's. Love the tire, but I'm trying to figure out my best tire pressure for wear and gas mileage. They are E load tires, so the tire states 80 psi- but I'm not usually loaded to the gills. Im afraid I will wear them in the center prematurely. The tire center gave them to me with 35 psi which seemed far too low. I'd appreciate any opinions, thanks

 

Generally you should run your tires at whatever the sticker on the inside of your drivers side door says.

That'd be 35 psi.

 

I have the exact same tire in the exact same size -275/70-18 or 33x11.50-18- and I run mine at 42 psi front and 40 psi rear. This is from another forum but post #8 by jwt873 is a great explanation of what psi to run! http://www.fordf150.net/forums/viewtopic.php?t=49987
When you move from a P rated tire to an LT the recommended PSI listed on the door sticker really is no longer valid as you've changed to a 10 ply load range E tire with completely different load ratings than what came from factory.

 

I always recommend 65psi unloaded and 80psi loaded on E rated or LT tires. Seems like 65 gives a nicer ride without killing the tires.

 

I run my nitto trail graps at about 40 psi. You can run the front slightly higher because of engine weight. That's what I've always noticed and done. For me made my tires wear even and nice through multiple vehicles.

 

I'm runnin 33's also. I went from 35psi to 45/50 and made a difference in gas mileage for the better. 35 was 2 soft. 45/50 seems just right for me...not running heavy loads.

 

I run 40 on my Terra Grapplers. To me, that's a nice in between of comfort and gas mileage. Although, the 10 plys are rough no matter what haha

 

Why would you follow the stock tire guide for after market off road tires ??

 

If you understand how tire pressure works, you understand why.

It's not about a volume of air, so in theory tire size doesn't matter. Obviously it's just a starting point, but I sure wouldn't be running 80psi in my 1000 dollar tires.

 

That would be for stock size and load rated tires. If either of those are different the door jamb isn't an accurate guide.