Sub weight/tire pressure

[85k5mudtoy]

Ive searched and found a few threads with the formulas, chalk tests, and temperature tests as to how to figure out the ideal tire pressure.

Does anyone have a good weight for a suburban? First problem is that the jam sticker is gone and I know that they werent accurate as to the actual loaded, ready to go down the road, weight.

I have 315/75/16 Kumho KL71 mud terrains on it that are E rated and good for 3860 lbs at 65 lbs of air. I started at 40lbs and it was all over the road. At 30 it got a lot better but im thinking that I will end up even lower.

 

[dhcomp]

Ive searched and found a few threads with the formulas, chalk tests, and temperature tests as to how to figure out the ideal tire pressure.

Does anyone have a good weight for a suburban? First problem is that the jam sticker is gone and I know that they werent accurate as to the actual loaded, ready to go down the road, weight.

I have 315/75/16 Kumho KL71 mud terrains on it that are E rated and good for 3860 lbs at 65 lbs of air. I started at 40lbs and it was all over the road. At 30 it got a lot better but im thinking that I will end up even lower.

All over the road? That sounds more like a steering/alignment problem than tire problem.

What do you mean by that?

 

[85k5mudtoy]

I do think that I need to get an alignment done. I did a quick measurement and with my crude measuring it looks like the toe is at "0". I think the tires being crowned dont help though.

 

[dhcomp]

Yep. Fix your alignment first, toe in 1/8" to 1/4", or it will hunt all over the road.

From there, i bet your tire pressure is in the 25-30psi range, but i've never run anything larger than a 33" tire, so i'm not of a ton of use.

Best of luck .

 

[4xcrazy]

I don't go any lower than about 25 pounds when I took it off road, then when I'd hit pavement, it was sloppy, spongy feeling, it was definitely a softer less harsh ride, but also more rolling friction, less fuel mileage, more tire wear.

Mine are 315/70/17's and are supposed to be max pressure at 50psi. I only run them at max pressure when travelling on the highway, less rolling resistance hoping for a bit better fuel mileage. I run them about 35-40 around town, never really was driven much anyways, but helps with any harsh road surfaces, I guess you could say a mix of in-between, happy medium, or whatever.

Tires are still wearing evenly.

"all over the road" tells me too, that you have front end sloppiness or alignment issues that needs tending to and it shows more when your tires are rolling aired up with less resistance.

Also low tire pressure builds up more heat as well. it's a MAJOR thing they drill in your head if you're a commercial truck driver.

 

[rebelgregory]

Not a suburban, but I daily drove my K5 on 35s at 27psi for years and got even wear and good handling.