Is Tire Pressure or Temperature More Important?

[dale farley]

A short video on pressure and temperature. https://www.youtube.com/watch?v=5Eu4D4eTu6A

[Joe Camper]

Being from Chicago and in trucking a few years prior I have some input I think.

When I was leaving for Florida every winter with the bus checking tire pressures is not just open and close.

The outside temps were always an issue. I always was left guessing where to have pressures on those colder winters.

I know when u stick a tire when its 20 degree out and the bus is stored outside I would not want 100PSI . Where to put it?

Until my tire monitors it was a guess. After them it was simple I could make sure pressure was good after 50 miles or an hr or so.

Most of U have things in a garage with constant temps that's ideal.

If U R outside even if its early and not too hot I learned from my pressure pro sensors that under those conditions the sunny side would be higher than the shady side with tires that were all previously set the same when all sides were shaded.

Sun and shade is a close second to variable factors only behind ambient temps.

U folks without pressure sensors R very deprived of a great accessory.

[Gil_J]

I have never seen a tire manufacture require anything except cold air adjustment. Cold is the tire temp before the tires roll. I have never seen a max pressure stated for tires heated above outside temperatures that come with road resistance and transfer of heat from running gear. With that said I seem to recall TPMS systems throwing a high heat alarm at 160 degrees or so.

Tire temperature is important, but I've never seen a specification. Proper alignment, speed, road surface temperature, and inflation are the main contributors to tire heat build up.

Don't under inflate and remember inflation charts only state the recommended minimum pressure.

[dale farley]

I prefer to run close to the maximum pressure in any tire. Although it doesn't provide the smoothest ride, it does provide the most protection against overheating.

[Joe Camper]

I tend to disagree with U Dale. Pressure Pro taught me that. They grow way too much when its real hot out at highway speed.

Gil I agree with the cold air pressure check but at what point is cold SO cold that it begins to too be cold for a correct pressure.

Like when Im going from 0 degree in Chi in Jan to 80 in Florida 16hr down the road.

I think the correct answer is U have to make an adjustment when the temps change that dramatically that quickly. Otherwise U will either be too low at 0 or too much pressure at 80. I used to run 100 in the rears. I would put 90 in them if it were down below freezing when I checked them before leaving and stick them again in the panhandle when Id get fuel the next morning.

What is max pressure for a 315 80 Dale? it will be 25lb+ more pressure at speed in the heat of the summer I don't know how comfortable that would make me.

[JIM KELLER]

Dale & Gil, Although I know you guys are right, I don't subscribe to your philosophy. When I bought the Bus I use to run the tires at 120 to 130, like the sidewalls say to do. I just couldn't stand the way the cracks in the highways pounded the Bus to death. Mile after mile I listened to the electronics, cabinets, hinges and blinds take a beating. I guess in my mind there is an in the middle trade off. I start off with 105 in the fronts and watch them climb to 128 to 130 as I run down the road. Duals start off at 90 and the tag at 95.

[dale farley]

Jim, I agree with you also. When I had the new tires installed, they put 100 in all the rears and 125 in the steers. On my CC, I was running 90 in all the rears and 110-115 in the steers. I intend to make some adjustments to mine after I have it weighed at the rally.

[Joe Camper]

Nitrogen does not grow at all and ive never seen any acceptations for nitrogen, so, if the manufacturer says say 90psi for a correct pressure for given weight and someone is putting max pressure of regular air in that's a huge amount of excessive pressure that is very unnecessary once we get rolling.

Truckers go from 28,000 to 80,000lbs empty to loaded and sometimes on a daily basis and I cant recall ever seeing a guy adjusting the tire pressure accordingly. U all have those Mack Daddy Michelins. U R all very good on service and maintenance, maybe U should not be so concerned about if U R doing right.

[Joe Camper]

Dale I realized U would be a prime candidate for Nitrogen.

U said u put max pressure in the tires to make yourself confident. What is max pressure 120.

If U put nitrogen they will stay there at 120. The guys who run 90 to 100psi of regular air that is where they will grow to with heat and speed right around 120.

[dale farley]

Joe,

I definitely plan to reduce the air in my tires once I get all the accurate weights at the rally. I now have a very stiff ride.