tire pressure setting

[wildwood]

Question: what tire pressure should i set my RV tires at?
max cold tire pressure on side of tire which is 50 psig
OR estimate based on load table which would be about 40

Also, should i set my tow vehicle at the max cold air pressure noted on outside of tire

We normally drive about 55 mph when towing


our tires are ST17580R13 for our 2001 prowler hybrid

cold pressure on side of tire is 50 psig

GVWR on RV is 4600 pounds

tire pres vs load followingLOAD/INFLATION INFORMATION FOR RV ST METRIC TIRES
Max
Speed
Tire Rating Inflation Pressure - PSI
Size (MPH) 15 20 25 30 35 40 45 50 55 60 65
ST175/80R13 65 670 795 905 1000 1100(B) 1190 1270 1360(C)


At 50 psig , load is 1360 pounds
At 40 it is 1190 pounds

I thought during towing i should use the cold pressure of 50
our dealer sets pressure at cold press of 50 minus 10==40 psig

at 40: 1190 x 4== 4760 which is ok vs a GWVR of 4600

Thanks

[rthrbelsewhere]

Hi wildwood..

First off, a couple of threads that I wrote up to answer a few of your questions.


Tire care:
http://www.forestriverforums.com/for...ghlight=sticky

Upgrade from 13" to 14" tires (another ton of capacity combined)
http://www.forestriverforums.com/for...ighlight=tires

When towing your TT, I can't say that you need to max out the tire pressure on your towing vehicle unless you are maxing out the capacity of the vehicle itself. I typically air up my rears to 5 lbs under the max inflation rating, but i have D rated tires. I really should have E rated on there, but I don't tow all of the time and i liked the size of bfg at ko's that i put on the pickup. One way that I can tell if i'm overloaded or under pressured is when I stop after an hour or so of towing. I walk around both the truck and the camper and lay my hand flat over the tread of each tire and feel for heat in the tires. (Learned that from a big rig driver) If they're cool, everything's okay. If they're hot to the touch (and you'll notice the difference) then I need to either move some weight around or add some more air, depending on where I aired them up before I left. I've always maxed out the trailer tires on the popup and they ran cool to the touch all the time, but I found E rated tires for it, so weight and pressure was never a problem. On my hybrid, those 13" wheels were always hot...i'm lucky i didn't blow 4 tires instead of just the 2 on the trip back from buying it in Iowa. Hence why i started the thread about upgrading the size of tire and rim on the camper. By the way, in the next few days, I will have the tires mounted to the rims and then have them mounted on the hybrid and if all goes well, i won't need a lift or anything extra to make them work. Measurement wise, the 14's that I found are barely any bigger then the 13" tires, but have a 1874 lbs weight limit per tire at 65 lbs of pressure and are D load rated vs the 1360 at max pressure for the 13's and C rated. Maybe you'll get lucky and if you decide to, 14's might work for you as well and relieve some of the pressure of having to watch over the 13's so closely. Pics will be coming soon to the 14" upgrade thread.

Oh...one more thing. No matter what you do, I think the idea of having some TPM's on the trailer are a good idea also since glancing at the trailer tires every now and again while on the road is difficult. Tire Pressure Monitors will help you detect problems before they become worse and overall is just a safety must for anyone with a trailer on for long distances.

Joe

[milzat]

50 psi

[Bama Rambler]

Most tire mfg's recommend running ST tires at max cold inflation. I'd recommend running them at that pressure because it makes the sidwalls a little stiffer thereby helping reduce the occurance of sway.

Since you don't say what your TV is I can't recommend what pressure you should run those tires at. If they're "P" rated tires I'd suggest running them at full cold inflation pressure because of the softer sidewalls. If they're "LT" tires I'd run them a few pounds higher than the load dictates.

[brittsnbirds]

A friend of mine who has been pulling TT's for a number of years recently had a new tire failure.

When he took the tire to the vendor they asked him how much air he was carrying in it. He told them 35. They honored the warranty but advised him to max them out on air pressure. He was told that the tire probably got too hot. It's ok to store them that way but before you take off you should put the maximum recommended pressure in them.

[wildwood]

Thanks everyone

I plan to go 50 on my new tires. i just them back and pulled the trailer home, very smooth. i will put between 35-40 in TV, a 4runner

we are going to gatlinburg TN camping over Easter, have a little fun, fishing, riding horses, walking around, enjoying some shows, going to sunrise service on Easter, looking forward to it.