Tire pressure

[trmiller]

We have a 1983 Excella 31 ft that we purchased last August. I right away put new trailer tires on the trailer. The dealer put 45 psi in the tires. The tires are 700x15LT load range D. Now the tires say max psi 60 lbs. I've pulled our AS at least 1500 miles since purchase. I did notice a little sway with 18 wheelers until I brought the tire pressure up to 58 lbs psi in each tire this last trip of about 500 miles. It just pulled much better. So the plate on the AS says 45 psi. The tires say 60 psi. I know at 58 lbs psi and this heat they are gauging out at about 63-64 lbs psi. So anyone been thru this before and what psi would you recommend based on what I've said. Wantvto keep this AS jewel safe.

[ROBERT CROSS]

Just what I do.....as the road temp rises rest pressure drops. Usually ck pressures and temp at every rest stop.


Normal pressures 60psi cold.

[trmiller]

So you run yours @ 60 psi year around ?

[6PackCharlie]

Usually put 55lbs in my tires. Have a tire pressure monitoring system (tpms) on the airstream tires so I can keep track of the pressure going down the road. When the tires get warmed up they generally stay around 60/61. The tpms is well worth the cost.

[ROBERT CROSS]

Originally Posted by trmiller

So you run yours @ 60 psi year around ?

Yep......1/2 in the basement. (take 'em off in Winter)

[bryanl]

45 is for load range C tires.

Always safest to run the tires at max sidewall pressure. Ride might be a bit rougher but the risk is much less to err on the high side.

Bob has good advice: check tire and hub temperatures when you stop for a break. They should run 120F or under depending upon conditions. If they run hot, add air.

[richinny]

this thread has some discussion about tire pressures:
http://www.airforums.com/forums/f438...hon-67407.html

[handn]

Originally Posted by bryanl

45 is for load range C tires.

Always safest to run the tires at max sidewall pressure. Ride might be a bit rougher but the risk is much less to err on the high side.

Bob has good advice: check tire and hub temperatures when you stop for a break. They should run 120F or under depending upon conditions. If they run hot, add air.

I agree that tires particularly LT tires should be run at maximum pressure.
A multi axle trailer doesn't turn the same way as a car. The sidewall is flexed when the wheel pivots. Maximum pressure diminishes the flex limiting the stress on the tire.

[Skater]

I'm going to disagree with the tires being inflated to max. If they are overinflated, the same issue that occurs with car tires would occur with trailer tires - namely, the center bulging, meaning reduced traction and increased wear. Inflate the tires to what Airstream recommends. For our trailer, the recommended pressure is 50 PSI. You can go a couple PSI above that (5, maybe even 10) without a major problem. More info from Carlisle tires here (PDF) but other brands have similar information available too.

Ideally you'd get the trailer weighed and figure out how much weight is on each wheel, then set the pressure based on that. The link above has a chart that will help you do that.

[ROBERT CROSS]

How do we then rationalize these quotes from the above Carlisle link?

"maximum load range is attained only when the tire is set at it's maximum air pressure. There is no advantage to taking air out of the tire."

"The above table DOES NOT endorse the reduction of air pressure. Carlisle Tire & Wheel only recommends and only warrants tires maintained @ the max air pressure while in service."

I see no advantage in reducing tire pressures just because I am not carrying the tires max load.

FWIW...I consider max pressure for our D range to be 55-60 psi. and stay with-in that range.

As was noted in previous post, dual axle trailers do not track the same as your TV and the sidewalls must withstand higher stress.

I believe most failures are caused because of damage caused by heat/under-inflation.

my 2cents

[DKDarrow]

Originally Posted by ROBERT CROSS

Just what I do.....as the road temp rises rest pressure drops. Usually ck pressures and temp at every rest stop.

You aren't really saying that as the road temp increases and therefore the tire pressure drops?????..............Perhaps "rest" pressure has some meaning that I am not familiar with. In my experience as the heat of the day increases the heat of the road surface that the pressure of the tire and temperature of the tire itself, rises accordingly.

For me, I use a tire presssure monitor system on the truck and trailer. Am currently going on perhaps 7 weeks on the road with 2 situations where the system totally saved in one case a tire itself, and the other damage to the trailer wheel well................WORTH THE EXPENSE.

After replacing a blowout in St. George, Utah, where the tech demanded that we up all the trailer tires to the highest recommended on the sidewall..........We had been running 60 psi but now upped it to 65.......

It does run straight and true at 60 psi and now at 65. At 50 psi I get LOTS of sway from trucks etc..................

As far as the comment about tire wear by high inflation. Have had this unit for going on 12 years and have yet to wear out tire one. As is the situation with most of us.......Instead the 3 to 4 year replacement issue raises it's head instead of the tire being worn out..............

YOU are familiar with the concept of replacing the tire at 3 or 4 years?????????????????????

God bless...............Dennis

[ROBERT CROSS]

Originally Posted by DKDarrow

Just what I do.....as the road temp rises rest pressure drops. Usually ck pressures and temp at every rest stop.

Realizing that max pressure on the sidewall is done cold.

My bad....cold=rest.

I do adjust pressures to compensate for the higher tire temp. I usually start out a trip at 55psi and adjust if needed. On last years desert trip the "adjusted" pressures resulted in a low cold pressure.

if YOU was directed at ME......YES!

Bob

[thecatsandi]

Ignore the plate and follow the tire. The air pressure depends on the load range and the weight each tire is carrying. I have Goodyear Marathons Load Range D and I run them at 70 PSI. The side wall says 65 Max. However, Goodyear has a supplemental document that says you can at higher pressures. If I run them at 65 they wear as if under inflated. That means they are running hotter than they should.

[trmiller]

Good information people! I appreciate all the advice and info. Everytime I stop I do check temp and pressure. And as stated earlier did find rather warm tires even in cooler weather at that 45 psi and when I increased to 60 psi they were much cooler and the trailer pulled better and a lot less sway from trucks. I pull very level if not more to nose with my Dodge 1500 Ram pickup quad cab. Probably back pressure back to or around 57-58 psi and see how it does. Can always adjust up if necessary. Always great info on this site..thanks

[Skater]

Originally Posted by thecatsandi

Ignore the plate and follow the tire. The air pressure depends on the load range and the weight each tire is carrying. I have Goodyear Marathons Load Range D and I run them at 70 PSI. The side wall says 65 Max. However, Goodyear has a supplemental document that says you can at higher pressures. If I run them at 65 they wear as if under inflated. That means they are running hotter than they should.

This is good advice - if the tire is running hot, it's underinflated. If you start seeing wear in the middle of the tire, it's overinflated.

The B190 requires the rear tires to be at 80 PSI because there's 6,000 lbs sitting on that rear axle...and each tire is good for about 3,000 lbs at 80 PSI. I watch that pretty religiously, after destroying one by having it underinflated.

[drag'nwagon]

Michelle is absolutely correct on this. When truckers start getting hot tires, they add air! I have seen people underinflate and get side wall blowouts. Inflate the tires to max cold pressure everytime you leave on a trip (and or check at reasonable intervals if you are gone for more than a week) and the only thing you will have to worry about is road hazards.

A max cold tire pressure will NOT harm your trailer!

[Beginner]

I have a 1984 31 foot Excella that is probally a carbon copy of yours (center bath/rear bed).
Mine weighs 8,000 lbs (3100 on each axle and 800 on the tongue).
That you have 700x15s to me means that you probally have LT tires just that they are bias ply but probally have a speed rating.
All that being said, I run 60 PSI in my LT225/75R16s.
Beginner

[ROBERT CROSS]

Learn something new every day.... 60psi=70psi.

[Zigidachs]

We just had our tires rotated after 5k miles, and on direct questioning, the tech. advised that we should always run the tires at their max. rated pressures, regardless of weight, because the more under inflated the tires are from their max. psi, the hotter they will become. So I always run at max. psi...cold....measured in the am.

And NEVER let air out of a hot tire.....

We use a tire pressure monitoring system (Truck Monitoring System) and it is more accurate than my pencil pressure gauge..In the morning I just look at the monitor in the truck, and it saves me the inconvenience of having to check each tire before departure.

[ROBERT CROSS]

[QUOTE=Zigidachs;1027220] And NEVER let air out of a hot tire.....

...blow on it 'til it cools down..

Then check it with the sooper accurate "tire monitor".