BigBRUNO4

What is wrong w/ d's?? Just askin, cuz I still got stock pichelins on mine.

Katmandu

I stand corrected. I got it mixed up with my other truck's placard.

Thanks for the catch.

Katmandu

Actually, double d's a GREAT!

Seriously, our Diesel trucks require "E" Load Range tires.

D Rated tires "can" give squirly handling, poor tread wear and worst "could" become overloaded and cause a blow out (in the worst case).

Read this thread about "D" Rated tires.....

https://www.dieseltruckresource.com/...ad.php?t=96191

jasonjones

My truck came from the factory with 245 "E" tires. The sticker pressures are 65 front and 80 rear. When I bought my truck (used w/60,000 on it) it was wearing brand new Goodyear Wrangler MT/R LT285/75R16 tires on Eagle Alloy 16 x 10 wheels. These tires got awesome traction in the dirt. They would tear up the ground just driving my truck slowly across the yard! The bad news was that they only lasted about 15,000 miles and the tread was very thin. I was really disappointed at the life of these tires. I have buddys that run MT/Rs on their 1/2 ton pickups and get good life out of them. The only thing that I can figure is that they are not built for a 7000# truck. While I was shopping for new tires, I found a guy that had an '02 truck that he pulled the factory aluminum wheels and 265 Michelins off at 8000 miles. I bought the wheels, tires, lugnuts, and center caps for less than I could buy 4 new Michelins for. I have run these tires at 65 psi front and rear and they have lasted around 40,000 miles. I think (hope) that they will last me until next winter.

HOHN

The door panel is NOT completely useless just because you put on oversized tires.


You can use the door jamb recommendations as a good starting point for CALCULATING the proper tire pressure.


So, here's two things to keep in mind:

1) HOW TO CALCULATE "proper" TIRE PRESSURE FOR STOCK TIRES:

• Manufacturer rates the tire of carrying X load at a certain psi. Say your factory 265s are rated for 3400 lbs @80psi.
• Weigh your truck to get axle weights. and divide by two to get load on each tire
• adjust pressure to fraction that load is of max. For example, if you have 1700lb on each tire (which is half of max rating of 3400lb), then you should have half the pressure-- 40psi, instead of 80psi.
• I find this is a good overall method, but can result in pressures that are too low at light loads. So, feel free to go OVER this pressure, but NEVER UNDER it. If you figure tire pressures this way, it's often good to use a (calculated +5psi) rule of thumb. This is because the calculation can't account for tire carcass rigidity, so pressures will be too low on the low end.

HOW TO FIND THE RIGHT PRESSURE FOR OVERSIZED TIRES:

• Begin with the "ideal" pressure you ran in your stock sized tires.
• Find the percentage oversize that your new tires are. For example, if you go from 245-75 to a 285 tire, the percent oversize is ([245-285]/245) or 40/245, or roughly 16.3%
• Reduce tire pressure by the same percentage. If your "ideal" pressure was 50psi before, you should lower pressure down to ~42psi with the 285s over the 245s.
• Rim width effects may cause a different pressure to be more appropriate. For example, a 315 on an 8" wide tire is at the bottom end of the proper wheel range, so it will "want" a little less tire pressure for proper wear. That same 315 on a 10" wheel will "want" MORE tire pressure for proper wear. A 315 is "ideal" on a 9" wheel, so you wouldn't need to adjust pressure based on rim width factors.

Time, experience, and personal preference will cause you to fine-tune your ideal tire pressures over time. But the above methods are VERY GOOD starting points.


Justin

HOHN

Your tire's didn't last long because a 10" wide wheel is TOO WIDE for a 285 tire. Heck, a 10" wheel is the WIDEST you can go with a 315! With a 285, it's too wide.

That, and MT/Rs are just too soft to hold up to a heavy diesel pickup. Try a harder tire like a Cooper STT or ST or a Toyo M55.