Tire Air Pressure

[youngone]

Just picked up my new GMC 2500 6.0. Tire are Michelins size 265/70/R18E. Tires are set from dealer at 70lbs. What is the best tire pressure for towing my 8000lb TT. Max PSI is 80lbs
Truck is used more for everyday driving. Also for everyday driving what is best tire pressure for ride and wear. Thanks!

[Cummins12V98]

jus2shy wrote:

Cummins12V98 wrote:


Your front tires will be worn out in no time with that low of pressure on the front with the heavy Cummins up front.

You have the 45 rear part right now air up to 72 in the front. The ride won't be much different and your tires will last.

If a 150 ride is more important than disregard the above.

That's what I initially thought as well, 60psi is recommended up front. Running at 60psi unloaded, I wasn't getting the full foot-print on the road. I was getting like 3.5 ribs out of 5 ribs contacting the front patch. I think it might be due to RAM using a wider tire now a days. Stock tire size is now 265/70r18. Far wider than the 245's used on duallies and older trucks. So I had to air down to ensure that the shoulders were bearing some of the load versus center tread.

Keep a good eye on them. What a lot of people don't realize is the contact patch on the front increases when you apply the brakes. Also when turning the edges will wear even more with less air pressure.

[jus2shy]

Cummins12V98 wrote:


Your front tires will be worn out in no time with that low of pressure on the front with the heavy Cummins up front.

You have the 45 rear part right now air up to 72 in the front. The ride won't be much different and your tires will last.

If a 150 ride is more important than disregard the above.

That's what I initially thought as well, 60psi is recommended up front. Running at 60psi unloaded, I wasn't getting the full foot-print on the road. I was getting like 3.5 ribs out of 5 ribs contacting the front patch. I think it might be due to RAM using a wider tire now a days. Stock tire size is now 265/70r18. Far wider than the 245's used on duallies and older trucks. So I had to air down to ensure that the shoulders were bearing some of the load versus center tread.

[Cummins12V98]

spoon059 wrote:

lightfoot wrote:
x2 on the door post. can't go wrong with the OEM's numbers.

Ask a 90's Ford Explorer owner with Firestone tires...

You are so right!

Might be why they have CYA numbers now.

[spoon059]

lightfoot wrote:
x2 on the door post. can't go wrong with the OEM's numbers.

Ask a 90's Ford Explorer owner with Firestone tires...

[Cummins12V98]

rhagfo wrote:

dbbls wrote:
Look on the door post and air up accordingly.

Cummins12V98 wrote:
Weigh your combo loaded and TV seperately. Use tire weight/inflation chart.

My Ram 2500 4x4 Cummins empty 72 front 45 rear rotate about 15k. Michelins or BFG's I easily get over 100k on a set. I would guess for you 65 front.

I go with Cummins12V98 on this subject! The door post is for MAXIMUM load not daily driving. Running the rears at 70 empty, will;
shorten tire life
result in reduced traction in wet weather
result in harsher ride when empty

I also run about 45# empty, loaded about 70# (80# max pressure), loaded for bear my rear axle is about 5,200# tires rated at 6,830#.

Thanks!
The door numbers are CYA! I am not a sheep and use the tire inflation charts. That is why I get easily over 100K on my tires.

[Cummins12V98]

jus2shy wrote:
Not sure how it is with your truck, but my RAM 3500 only had 1 pressure recommendation and that was for max load. The ride was pretty jarring at first. So I experimented by dropping the rear axle PSI to match the front axle at 60 psi. Vast improvement in empty ride. So now I've dropped the front to 55psi and rear down to 45psi. It rides as well as my 2010 F-150 with Bilstein 5100's and goodyear duratracs installed. So I'm very happy with the ride now. I also carry a decent air compressor around in case I get asked to haul something of any significant weight (rock, soil, etc...). So no worries if I end up driving to the home improvement store and having to bring something back that's heavy.

Your front tires will be worn out in no time with that low of pressure on the front with the heavy Cummins up front.

You have the 45 rear part right now air up to 72 in the front. The ride won't be much different and your tires will last.

If a 150 ride is more important than disregard the above.

[ghostrider42]

Sometimes the door sticker doesn't match the tires that are on the vehicle, which was the case with my 95 Dodge. The door sticker said 245/75R16 @ 55psi. The tires were 235/85R16 @ 80psi - so I ran 65 unloaded and 75 loaded.

[rhagfo]

dbbls wrote:
Look on the door post and air up accordingly.

Cummins12V98 wrote:
Weigh your combo loaded and TV seperately. Use tire weight/inflation chart.

My Ram 2500 4x4 Cummins empty 72 front 45 rear rotate about 15k. Michelins or BFG's I easily get over 100k on a set. I would guess for you 65 front.

I go with Cummins12V98 on this subject! The door post is for MAXIMUM load not daily driving. Running the rears at 70 empty, will;
shorten tire life
result in reduced traction in wet weather
result in harsher ride when empty

I also run about 45# empty, loaded about 70# (80# max pressure), loaded for bear my rear axle is about 5,200# tires rated at 6,830#.

[jus2shy]

Not sure how it is with your truck, but my RAM 3500 only had 1 pressure recommendation and that was for max load. The ride was pretty jarring at first. So I experimented by dropping the rear axle PSI to match the front axle at 60 psi. Vast improvement in empty ride. So now I've dropped the front to 55psi and rear down to 45psi. It rides as well as my 2010 F-150 with Bilstein 5100's and goodyear duratracs installed. So I'm very happy with the ride now. I also carry a decent air compressor around in case I get asked to haul something of any significant weight (rock, soil, etc...). So no worries if I end up driving to the home improvement store and having to bring something back that's heavy.

[dennisgt60]

Read the owner's manual section related to tires. Follow the manuals advice.

[Cummins12V98]

Weigh your combo loaded and TV seperately. Use tire weight/inflation chart.

My Ram 2500 4x4 Cummins empty 72 front 45 rear rotate about 15k. Michelins or BFG's I easily get over 100k on a set. I would guess for you 65 front.

[lightfoot]

x2 on the door post. can't go wrong with the OEM's numbers.

[dbbls]

Look on the door post and air up accordingly.

[Jbechtoldt]

youngone wrote:
Just picked up my new GMC 2500 6.0. Tire are Michelins size 265/70/R18E. Tires are set from dealer at 70lbs. What is the best tire pressure for towing my 8000lb TT. Max PSI is 80lbs
Truck is used more for everyday driving. Also for everyday driving what is best tire pressure for ride and wear. Thanks!

I run 80psi in tv when towing and 65psi not towing