PSI on Tow Vehicle

[Mac]

Interesting that my Montana dealer said to make sure the tires were inflated to 80 which is the maximum. I never inflated my old fifth wheel to the max prefering to keep them about 5 lbs under. So I wondered what everyone does on their tow vehicles. My tires on my truck are rated for 80 but I usually run 70 in the front and 75 in the rears. I was curious to hear others opinions.

Thanks,

mac

[Bill Frisbee]

The specs on my Ram 3500 are to run 60 psi in the front at all times. max psi with full load on rear tires is 75 psi. I run 70 psi in the rear when hauling the Monty and 50 psi otherwise. Tires are BFG Rugged Trail T/A LT265/70R17E

[Bill Frisbee]

Also forgot to mention that my Montana dealer inflated the RV tires to 75 psi ... Tacoma LT235/85R16. But I will be replacing them with tires in which I have greater confidence next spring.

[ols1932]

Look at the sidewall of your tires. You will see the inflation pressure molded there by the tire manufacturer. That's the pressure recommended by the tire manufacturer for maximum wear of the tire. In my case, my tires are LT23585R16 which call for 80 lbs cold. That means that before you move your rig in the morning, check the pressure. Be sure you use a good, accurate tire pressure gauge. If any are less than 80 lbs, if you don't have your own compressor, fill them at a service station. If a tire measures at, say 75 lbs before you start and it reads 80 when you get to the service station, the tire is still 5 lbs light. Add 5 lbs.

If you run tires very long at lower than the recommended pressure, the tread wear on the outside will be extreme and the sidewalls will be weakened. Likewise, if you pressure them up over the recommended cold pressure the middle tread will wear abnormally.

If you talk to any tire manufacturer they will tell you to go with the cold pressure recommended.

Remember the law suits between Ford and Firestone.

[wileecoyote985]

Mac;

The vast majority of tire problems are caused by under inflation. Under inflation causes the tires sidewalls to flex excessively. This causes a large build up of internal heat from friction that the tire simply cannot dissipate quickly enough. Sooner or later somethings got to give and it does. Warm weather and hot pavement both contribute to these failures.

I run my tire pressures on my tow vehicle and Monty at the max recommended cold pressures when towing. We (Montana owners)are carrying a LOT of weight when we're towing. Better to be safer and sacrifice ride quality a little, than to be sorry.

Gary

[Jeff Heiser]

I always run TV and TT tires at recommended pressures. In over 25 years we have not had a tire related problem. Many friends have and most of them never checked or ran tire pressures at the recommended levels.

God Bless America
Jeff Heiser
Merritt Island Florida

[Mac]

Jeff,

I wish you could have driven the old motorhome we had so you could have had the experience once or twice. We had so many blowouts in that old rig that I threatened to leave it on the side of the highway. Once both I lost the duals before I could even pull over to the shoulder. We started carryting two tires on the top, looking like a couple hillbillys but we couldn't find the 16.5's most places. Funny thing is we never had another problem so I started calling them my lucky tires!

Never had a problem since, and just trying to avoid future ones.

Thanks for your input!

mac

[Fordzilla]

I run my traailer tires @ 80 all the time. Also run all 4 truck tires @ 80 during the summer. That way I don't have to air them up for the weekends when we move the trailer, then air them down the rest of the week. I do however, air them down after I put the trailer in storage for the winter. Helps to get a bigger footprint on the snowy roads here. Like was mentioned the biggest tire killer is underinflation. So, I have been studying and plan to get a tire pressure monitoring system before long that will warn me if a tire starts to go low before I have a blowout.

[sreigle]

I have the exact same tires and tire size as Bill Frisbee. I run 80 in the rear and 65 front when towing. If we're in an area with rough roads or we are planning some backroad gravel road trips I'll drop rear tires to 65. Otherwise I leave them at 80.

I run the max 80 on the rears when towing because our pinweight is 3300 lbs and we're loading those tires to the limit.

[virgil47]

Hard to argue with Jeff and 25 years experience and I had heard this before in this forum so I have always kept all 8 tires at 80psi as recomended on the tires themselves. My tires are LT245-75-17,E rated.

I also learned from this forum that under inflation is the cause of most tire failures so I bought a good guage and a compressor and check everday that the trailer moves.

One thing I experienced on this trip from Georgia to Maine is that as the weather gets cooler, the tires need air. Twice along the way, I had to add roughly 5 pounds to all 8 tires. (Did not think of the spares until this minute)

[Montana Sky]

I run 80 on coach and when towing on the truck as well. Not towing I run my truck at 60psi (cold, so far so good.