Tire Pressure with New Montana

[Bill and Ann]

I have been reading all the posts on this subject and decided I could add one more. I am a firm believer in weighing my vehicle before each big trip south to ensure I am not overloaded. The one thing I notice each time is that the weight is not transferred to the front wheels. I weigh hitched up and unhitched so that I can see my pin weight. The weight on the front wheels does not change by any more than 10 lbs on both weighs. I carry 65 in front and 80 in rear. I was carrying 55 in front but an inspection of my tires resulted in me increasing the pressure to 65. I think, my opinion, that 80 in the front is going to cause tire wear.

If you can't play a sport....Be one.

Bill and Ann
Napanee, Ontario, Canada
2004 3670RL Big Sky
2003 GMC 2500HD Crew Cab 4x4 Short Bed
20K.Reece Hitch
Duramax/Allison
Prodigy Controller

[sheiba1]

"Go with the tire pressures recommended by Ford"

Well Glen isn't this what got Ford into the very large lawsuit in affiliation with Firestone on who was right on tire pressure. It sure gave the vehicles in question a smooth ride, after all is that not what the Vehicle manufactures want you to notice. I find it hard to believe you have not run across this "scientific mathematical formula" seen as it came from the tire industry! I am not a tire expert but I have used a few tires in my lifetime with no problems and have never worn out the centers by using max pressure. But that is the beauty of these forums you can give Information, you can take information or you can ignore information!
Have a good day
Rich.

[steves]

Well for all you technical Gurus, I have attached a reply I made on the post "tire pressure" awhile back. It is documentation I got from a tire seminar I attended at the Daytona Good Sam "Rally" from last April. The overall statement made was to run your tires equal to the load they were carrying (you can go to tire mfg websites and see the load tables and the recommended tire pressures) and they encourage to error on the higher pressure side as low tire pressure generates heat and that's what attributes to most tire failures. I rum my truck with 65 front and 80 rear (when towing) and I was within the load ratings (I had my 3400 weighed there).They recommended to bump the front to 70# when towing as a safety margin. The other reason for tire failure is age....any tire older the than 7 years is at risk. To determine the age you need to look on the back side of the tire to see the mfg date. Be aware that tires can lay around for a couple of years before they are used and can be exposed to the ultraviolet rays which is the main cause of the rubber compounds deterioration.

I agree with running too high a pressure will wear on the middle of the tire just as running too low will wear on the inside and outside edges. The correct pressure is only known if you know the weight on your axels. Additionally I have attached a statment from my documetation from the Tire and Rim Association that recommend you can increase tire max rating by 10# to reduce heat:

Attachment from previous post
This an extract from the documentation I got from RVSEF when they weighed my 3400.

"The tire and Rim Association standards permit increasing the pressure of Light Truck (LT) tires up to 10 psi over that shown on the sidewall, and up to 20 psi for truck tires". "This DOES NOT increase the rating of the tire, but helps it to run cooler".


Steve & Betty (AKA steves)
2005 3400RL Montana
2006 F350 PSD SRW CC LB 4X4 King Ranch

[sreigle]

quote:Originally posted by Bill and Ann

I have been reading all the posts on this subject and decided I could add one more. I am a firm believer in weighing my vehicle before each big trip south to ensure I am not overloaded. The one thing I notice each time is that the weight is not transferred to the front wheels. I weigh hitched up and unhitched so that I can see my pin weight. The weight on the front wheels does not change by any more than 10 lbs on both weighs. I carry 65 in front and 80 in rear. I was carrying 55 in front but an inspection of my tires resulted in me increasing the pressure to 65. I think, my opinion, that 80 in the front is going to cause tire wear.

Bill, I'd guess your hitch pin center is exactly over the axle center. Mine is slightly aft, apparently. Every time I've weighed ours the front axle is about 20 lbs lighter hitched than unhitched. I don't think it's enough for me to worry about but it does tell me I don't need to change the psi in the front tires for towing. I do air up the rear tires to 80 psi.

See another Montana or Mountaineer on the road? Flash lights twice, it might be one of us!
Steve Reigle (pronounced Regal)
Fulltiming since 3/21/03
'07 3400RL
'05 Ford F250 SD Lariat CC SB 6.0L PSD/TS FX4 4x4

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