Front tire pressure?

[Ramblin__Ralph]

Rig: 2006 GMC 2500HD with 2001 Lance 845 camper. Tires are Michelin LT265/75R16.

My door jam plate says:
Front 53 psi
Rear 80 psi

I have been airing up to:
Front 60 psi
Rear 80 psi

My axle weights with camper and loaded for long term travel are:
Front 3350 lb
Rear 5800 lb

That's just under my GVWR of 9200 lb.

Last summer I had my tires rotated when traveling and the shop said I had wear on the front (cupping IIRC) indicating not enough pressure. So they boosted the front to 70 psi (or more).

I'm getting ready to hit the road again for several months. What is the consensus on proper front tire pressure?

Thanks,

[sonuvabug]

Have the same size tires as yours with a ~ 3,200 lb. TC unit and a diesel motor. I run 65 psi on the front and 80 at back when loaded. No unusual tire weat and I rotate them annually.

[Ramblin__Ralph]

ticki2 wrote:
just noticed you have Bilstein shocks , so do I . The earlier model 4600 had a problem with the lower mounting bushing on the fronts wearing out. They replaced mine free . Might be worth checking yours . It would affect the shocks performance . Have fun camping .

Thanks for the heads up. Same thing happened to mine years ago. Had them replaced, but don't remember taking the warranty route. 😞

[ticki2]

Ramblin' Ralph wrote:
Been camping for a week. Thanks for the additional input!

just noticed you have Bilstein shocks , so do I . The earlier model 4600 had a problem with the lower mounting bushing on the fronts wearing out. They replaced mine free . Might be worth checking yours . It would affect the shocks performance . Have fun camping .

[Ramblin__Ralph]

Been camping for a week. Thanks for the additional input!

[Grit_dog]

Tread design and where you drive has everything to do with how tires wear.
Best case, closed shoulder tread and straight roads. Worst case open lug shoulders with large void ratio and hairpin turns.
This is a case of understanding what you're doing with your rig and how it's reacting.

[jimh406]

I agree cupping could be tires. I changed my fronts (stock size 19.5 225) from Hankook DH01s to Bridgestone M724Fs and no more cupping even though I’ve used the Bridgestones longer. No alignment or additional shock changes either.

BTW, the Bridgestones are also all position whereas the Hankooks were drive tires. My SRW also cupped the Hankook DH01s in 245 size. Not a huge problem since I still had 40K on them when I traded, but I switched to the Bridgestones because we were doing a lot more highway driving. I just saved the Hankooks for spares that I took off the F450.

[ticki2]

Ramblin' Ralph wrote:
Rig: 2006 GMC 2500HD with 2001 Lance 845 camper. Tires are Michelin LT265/75R16.

My door jam plate says:
Front 53 psi
Rear 80 psi

I have been airing up to:
Front 60 psi
Rear 80 psi

My axle weights with camper and loaded for long term travel are:
Front 3350 lb
Rear 5800 lb

That's just under my GVWR of 9200 lb.

Last summer I had my tires rotated when traveling and the shop said I had wear on the front (cupping IIRC) indicating not enough pressure. So they boosted the front to 70 psi (or more).

I'm getting ready to hit the road again for several months. What is the consensus on proper front tire pressure?

Thanks,

According to these numbers you have more than enough air in the tires . My 03 diesel calls for 60psi with 245's . With 265's they only need 50psi for the same weight. Something else is causing the cupping . It could be the roads , front end wear / alignment , or even just the nature of the particular tires .

[Paul_V1]

I rotate every 5K miles and run front and back at 80psi. I have been doing this for the last 18 years with this truck with zero problems. I tried once with 65psi in the front and it was kind of sloppy going down the freeway.

[deltabravo]

Ramblin' Ralph wrote:
I'm getting ready to hit the road again for several months. What is the consensus on proper front tire pressure?

Thanks,

Do the Chalk Test. Lots of examples on YouTube of how to do it.

[MORSNOW]

BradW wrote:
I could really tell the front end had a significant effect on the side to side rocking when I had Rancho 9000 adjustable shocks on all four corners of our srw trucks. I experimented quite a bit with different setting and I found that without the camper I needed run the front socks on nearly the softest setting and with the camper I needed run the front shocks on nearly the stiffest setting. The front shocks had almost as much (maybe 70% - 80%) effect as the rear shocks on reducing side to side rocking.

bradw

Thank you for the additional information, I may play with my front pressure.

[BradW]

MORSNOW wrote:

BradW wrote:
When we hauled our Lance on our SRW trucks, I had less sway when we ran the front tires at 80 psi. Tires are part of the suspension and when the rear rocks side to side, the front does also. So anything you do to stiffen the front suspension helps, even though 90% of the added load is on the rear tires.

I honestly never thought about the front tire pressure and sway before due to almost all of the weight is added to the rear. Hmmm

I could really tell the front end had a significant effect on the side to side rocking when I had Rancho 9000 adjustable shocks on all four corners of our srw trucks. I experimented quite a bit with different setting and I found that without the camper I needed run the front socks on nearly the softest setting and with the camper I needed run the front shocks on nearly the stiffest setting. The front shocks had almost as much (maybe 70% - 80%) effect as the rear shocks on reducing side to side rocking.

bradw

[BradW]

towpro wrote:
C is max PSI (marked on sidewall)

I have never seen an E rated tire with the maximum psi shown on the sidewall. What is shown is the maximum load of the tire at 80 psi.

bradw

[Grit_dog]

If there is nothing wrong with the front end, simply driving highway speed on predominately curvy roads (your location is the CA coast, not too many straight roads there) will feather front and rear tires pretty quickly.
Learnt that when we lived in the mountains. Almost couldn't rotate truck tires fast enough to prevent it, when the daily drive was 60-70 mph through the mountains.
Yes cupping is different (1 tread high, next one worn lower) and can/is an indicator of shocks or other front end issues. But where you drive, type of tire and load contribute to both.
That's why heavy vehicle steer tires typically have closed shoulder treads. A heavy pickup running AT or MT tires is just trying to chew the front tires up. Just how it be.

[Ramblin__Ralph]

Many thanks for input and the formulas! My shocks do have a lot of miles, so that could be causing the cupping. Tires are load range E, 80 lb max, one size up from the OEMs.

Yes, I should have used the word "opinion" vs. "consensus". 🙂

Ralph