Well I have gotten so many opinions on what my tire pressure on my new tires should be. So I thought you guys might be able to help. I just bought some 285/75/16's I use to have the 265/70/16's. Ive been told to keep with the 35 psi Big O tires who sold em say 52-55 and some say max wich is 65. So whats it gonna be. Thanks in advance for any helps or any leads. I dont know if this will help but my truck is a 03 XLT 5.4 Extended Cab 4x4

 

Well, I think you're just gonna' find a whole bunch of more differing opinions here, but anyway. To help us all out, are you tires Passenger (P285/75/16) or Light Truck (LT285/75/16)? (What brand & type of tires are they?) Also, what's the max load rating? This makes a difference.

If it were me, I'd keep them at 50% max pressure plus half of your load percentage. For example, if your tires have a max load of 2000# each, and you have a normal unloaded F150 (5000#), your load percentage is 5000 ÷ 8000 = 62.5%. Half of this (31.25) plus 50% (for nominal pressure) is about 80% of max tire pressure. Then if your max tire pressure is 65 psi, I'd fill it to 52 psi. Change the numbers for your application.

If that's too much trouble, I'd just say that 80% is usually good.

 

That was pretty impressive,

I think I got what your saying I have the Yokohama Geolander A/T II LT285/75/16D With a Load Pressure of 3305@65 at cold inflation. I was also curious about the "D" after the rim size(16) if you can help me with that too would be appreciated.

 

If your truck's unloaded and not towing, I'd run those tires at about 45-48 psi. Then just make sure they look right on the ground. There should be a slight bulge near the road surface, but not a large one; and the tread should look flat, not rounded.

Well, at first I thought it might be the speed rating, but a "D" speed rating means 40mph, so that can't be right. Then I thought it might be the load rating, but load ratings are usually numerical.

Then I decided to look at your tire's specs. I found them at http://www.yokohamatire.com/pdf/geoatpls2.pdf. What I found was interesting - your size is the only size that doesn't have a load & speed rating shown, and it's also the only one that shows that "D."

So, in summary, I'm not really sure what that means. You may try calling Yokohama (1-800-722-9888) and asking them. If you find out, please let us know. I'm curious.

-Jeff

 

'D' is a load rating - I don't know what the max load is, but it is max load is at 65 psi. 'E' rated tires max load are at 80 psi.

 

Load Range also has to do with number of ply's the tire has, "C" is a 6 ply, "D" is an 8 ply and "E" is a 10 ply.