Tire pressure help?

kazuaki · December 18, 2002

Well, my 4 day old '03 K2500 Sub got its first mod. I traded the weenie stock tires in and got a set of 285/75-16 Goodyear Wranglet MTR's. These things look mean! I need some recommendations on tire pressures, though. The door sticker on the Sub says 50psi front and 80psi rear. That seems kinda crazy to me. I would like to set the pressure so that the ride is not overly harsh, but the tires still need to be able to handle the load of the Sub plus a large trailer. Any advice would be greatly appreciated!!!

Shaners · December 18, 2002

I run my 265/75/16 load range "E" Michilins @ 50 psi frt and rear.

80 psi rear is the max, and is recommended for when you have a full load both in and behind your Suburban. ( like 4 passengers and 1500 lb tounge wt and 10,000 lb trailer.)

You didn't mention what "load range" your new MTR's are, and you definatly don't want to exceed the max pressure that is on their sidewalls.

Also with 285's on the narrow stock wheels you don't want too much air in them or they will crown and you will quickly wear out the centers of your new tires.

kazuaki · December 18, 2002

It's interesting because my stock tires were load range E and rated at 3042lbs @ 80psi. My new tires are load range D, but are rated at 3305lbs @ 65psi. Maybe the larger size more than offsets the lower load range? Anyway, I think I'm fine there. I just wish I knew where to set the pressure for the most even wear, but I'm guessing that isn't an easy answer. Maybe I'll just have to experiment. The pressures on the door sticker just shocked me because my '02 Tahoe was only like 30psi.

2001 HD · December 18, 2002

I have 265 D BFG's on factory 6-1/2" alloys. 65 in the rear and 59 in the front seems to ride good. Less in the rear the ride gets a little mushy and seems to roll more when cornering. Higher in the front makes ride a little "harder" 50 is way to mushy.

Unless you absolutely max out your payload, D range is only about 100LB/tire max weight rating less than E, depending on manufacturer.

There are several methods for determining the correct surface contact area, but IMHO the ride is the best way to decide what pressure to run. Crowning has not been a problem rotating every 6K. Tires should be at "Normal operating temperature" during evaluation.LOL

awdvkd · December 18, 2002

If you like the way the MTR's look wait until you put them on dirt or in the mud. They also have a indestructable sidewall. The bad thing is they pick up rocks really bad, oh well. Back to tire pressure, it was suggested to me that you find a flat area (concrete or asphalt) wet it down and with the tires aired to the max drive through the water and see if you have the whole tread on the ground. Deflate the tire until you have the whole tire pattern on the ground. My 2001 2500HD, 8.1 allison ended up with 55 in the front and 50 in the back, that was with GY MTR 265's. The max inflation was 65 psi. Hope this helps.