What tire pressure you running?

[Steve N Sal]

This will differ for everyones specific situation. For the weights we carry I have been running 95# in the fronts and 90# in the rears.

[RVNeophytes2]

Originally Posted by Chuck 1935

One thing that has not been mentioned in all of these tire pressure debates is tread depth. If you use a tread depth guage and measure the tread across the tire, it will give you a good indication of wether or not you are under or over inflated. If the center of the tread is thinner than the tire edge, you have too high a pressure etc.

I've "governed" tire wear on my planes this way for years, stretching out additional longevity. Until Chuck mentioned the technique, I'd never thought of it in the RV context.

The engineers don't make this stuff up. If the Michelin folks say 80 psi is optimal, I'd go with that. If that pressure results in some addl edge wear, you can use Chuck's technique and add 5 psi to focus wear on the center. I'd be hesitant about adjusting the other way.

Anyway, who of us really wears out tires? I'm doing 7,000 miles of driving a year, and people act like that's some kind of record for DPs.

[Mr_D]

Originally Posted by Chuck 1935

One thing that has not been mentioned in all of these tire pressure debates is tread depth. If you use a tread depth gauge and measure the tread across the tire, it will give you a good indication of whether or not you are under or over inflated. If the center of the tread is thinner than the tire edge, you have too high a pressure etc.

In all my years of driving I have yet to see a tire manufacturer recommend this method.

[Wayne M]

Use the "Chalk line" method will also tell you if you are over or under inflated.

Draw a chalk line across the tire. Roll forward for a short distance. Check the chalk line on the tire.

If the center of the chalk line is worn out, the tire is over inflated. If the outer edges of the chalk line are worn out the tire is under inflated. If the chalk line is evenly worn out, you are most likely at the correct pressure.

The best method is to use the manufacture's inflation table. Give yourself a fudge factor, never exceeding the side wall or manufacturer's maximum or minimum pressures.

When I mention fudge factor, if you are set at minimum, you have no room for fudge factor. If you are set at maximum you have no room for fudge factor. Fudge factor is additional weight, temperature changes (2% for every 10 degrees of change), altitude change, (.048 psi for each 1000 feet of change)

There are many posts on this subject.

Happy trails.

p,s., no one can tell you, without knowing all of the details, what the proper tire air pressure for your RV should be. All the 95, 90, 85, 100, 110 psi pressures being stated are what "they" run. Is your weight "exactly" like the weights of everyone posting their information. Maybe one or two, but no one has listed their weigh, their tire size, and manufacturer's recommended pressures. So the homework. You have a portion of the battle already won. You have a general weight across your axles. Use the manufacture charts, and your specific requirements, to ascertain the correct tire pressure for "you." As soon as you can, try and get a four corner weight on each tire/set of tires.

[DriVer]

Originally Posted by ctusdenny

I just purchased a National Dolphin MH a couple months ago. I haven't found a place to weigh it yet, so I'm wondering what others are using for tire pressures? I have the 22.5" XRV tires, with fronts at 90 psi, and the rears at 95 psi. I'd say the MH is moderately loaded as I have basically rid myself of the "nice to have" items, and simply keep the "must have" now.

With a 34 foot motorhome, I would start off with 85 rear and 90 front. You will be fine with those pressures until you get a weigh ticket.

[cmpncrsaider]

I run 100lbs on all 6 tires. This leaves room to fluctuate with temps. I think its a good compromise for ride and fuel economy.

[RVNeophytes2]

Originally Posted by Wayne M

Use the "Chalk line" method will also tell you if you are over or under inflated...

This is an interesting notion. I'll certainly give it a try. It makes sense, might be a great confirmation of manufacturers' values. Cool!

In the interest of safety, there are several posts in this thread where suggestions could be misinterpreted; and, under certain circumstances, lead to tire failure or insufficient performance.

Rather than address them directly, allow me to caution owners to follow tire manufacturers' guidance for the exact model of tire installed on your rig at the time, using weights for your operation per the tire manufacturers' guidance. Pressures that worked for the same rig with different tires (during certification or afterward), or inflation ranges for other rigs equipped with your same tires may not be appropriate.

[Wayne M]

[jth camper]

Originally Posted by Mr_D

In all my years of driving I have yet to see a tire manufacturer recommend this method.

As a former automotive aligment tech, that is a solid way of determining how the tire is wearing. To a trained eye you do not need a tire tread depth gauge.

I have been running my front tires at 105lbs and noticed a under inflation tire wearing pattern. I run the rear at 95lbs and are wearing great. At 11,000 miles I just rotated the tires to prolong tire life.

I was suprised by the under inflation tire wear on my front tire's, but I was advised by my "truck tire" guy that truck tires are a little different than car tires, which I'm learning. He advised That motorhome do not put enough weight on the front tire's to get a proper wear pattern. After owning my coach for one year and putting on 10,000 miles on the tires he is correct.

Just mt $.02

[Chuck 1935]

Originally Posted by Mr_D

In all my years of driving I have yet to see a tire manufacturer recommend this method.

They don't. It's much easier to use a recommended tire pressure than to expect Mr car owner to measure his tread deapth when he can't keep his tires properly inflated anyway.
Another thing they don't tell you is to look for feathering on the tire tread. That is a good way of determining if the toe is correct.

[Yondog]

Originally Posted by Arch Hoagland

I run my 22.5's at about the same pressure as you. Mine is weighed and pressure set at what Michelin recommends plus about 5 lb.
I had new front tires installed, due to alignment problems, and the dealer set the pressure to 110 pounds on the front.. Drove from Fresno, Ca to Sacramento, Ca and promptly dropped the pressure back down to 90 lbs. Terrible ride at that high of a pressure plus there was a bit of wandering.
The recommended pressure is where they should be set for overall use.

Although I haven't yet weighted my rig, I was a little confused about the tire pressure. My 22.5 rating was 110lbs but when I picked up the rig and got it back to our storage area I gauged all 6 tires and they were at 90PSI. we just got our rig in June and have gone on a few long weekends without much gear other than beach chairs and a BBQ. Will weigh it in the spring when we get to do some serious traveling. Guess I will keep them at 90
Thanks for the info.

Have a great Christmas

[N6CUS]

I run 88 cold all around, weight is 33,160 without my fat ass in it, full of fuel, water and supplies

[wa8yxm]

I see folks have already advised weighing the rig RV Safety, Merritt Island, Florida can link you to folks who come out and scale it for you.

Low pressure: Causes rapid wear on the outer edge of the tread, Excessive flexing of the side walls, (Leading to early blowout) and loss of control.. A bad thing.

Correct pressure: Full tread contact with the road, Even wear across the tread, Proper sidewall flex, Longest tire life, best control.

High Pressure, Excessive wear in the CENTER of the tread, Harsher ride, Loss of control.

The pressure on the sticker, at the best, is a guess.. May be right, Most likely not.

The pressure molded onto the tire is the maximum design pressure for the tire. has nothing at all to do with the PROPER pressure and should be ignored unless you are running at the maximum load (Which is molded right next to it) as I am.