Truck Tire PSI?

[Larv]

I'll be pulling a 29' TT to AK and am wondering if 65 PSI is a good pressure to run in the truck tires. The tires are the stock size but I replaced them with mud and snows. Schwabie inflated them to 45-50 psi for around town but they always looked soft to me. Thanks is advance!

Larv

 

[BigMike]

What is the tire rating? I'd inflate them to whatever the recommended pressure is for the tire. I inflate my E rated tires to 80psi cold all the way around when I pull my 5er.

 

[Jim Smith]

70psi

I keep mine at 70psi when towing. Got this tip a few years ago on this site.

 

[Kirwin]

Tire pressures

My advice is to get the tire sidewall data IE 235/85R-16 E off your tires and go to your tire manufacture's website and put in that tires data and look up the recommended inflation pressure off of the inflation pressure/load chart or table on their website. This combined with actually weighing you truck and trailer on a commercial scale to determine what each (tire if possible) axle is carrying will provide the best recommended pressure. Note that in your owners manual packet there should be a paper from Dodge with recommended pressures for your truck. My 03 DRW 235/80R-17 E's according to Dodge require only 65 PSI for full load. Keep in mind that there is a max inflation pressure on the sidewall that should never be exceeded and that all inflation pressures are cold inflation pressures. In my opinion its better to run a little higher pressure than lower pressure within reason. Also note that in most 3/4 and 1 ton SRW trucks, rear GAWR is frequently limited by tire load capacity at the maximum inflation pressure. IE each tire is rated at 3042# and GAWR is 6084# on my 97. Hope this helps. Ken irwin

 

[bombero]

You should look at the info that came with your CTD> Mine has Michelins and their brochure had lots of info on tire pressure. My advice for you is put the max in all your tires (whats written on the side wall) both your truck and TRAILER. Have a safe fun trip.

 

[LesStallings]

Do a search for tire pressure chart. The chart that Dodge supplies does say 65# for full load on my dually but in the fine print it also says add 10# for sustained speeds above 65 MPH.



75# is close to the 80# max listed on the tire. What you are trying to acomplish is reduce sidewall flex, which leads to high temperatures and failure.



When I tow loaded, I use 75# in the rear and 65# front. I am definitely at sustained speeds above 65 MPH. I also use an inexpensive Radio Shack IR thermometer to check the tread temperature (and center wheel bearing) at every fuel stop. I've been able to spot a tire running hotter that the others and on further inspection, found a nail in the tire (twice). It is better to change a tire in a truck stop than along side of the road.



The temperature measurement is quick and the comparisons will tell you a lot. Also, since tire pressure measurements must be made when the tire is cold, a pressure gage is best used before you hit the highway.

 

[RClark]

When you leave home, go thru Oregon. All the chickencoops leave the scales on.

Weigh the truck and trailer, axle by axle and use the chart that came with the truck to determine the correct pressure. My 2002 Ram 3500 towing a 13,000 5th wheel takes 50-55 in the front tires and a max of 40 in the duallys. the trailer can also be checked this way.

 

[Froadin]

A quick note on the temp guns, these are really easy and cheap to get at your local or online hobby store.

http://www.tempgun.com/order.html

is just the first example I found.

I have one very similiar to this and it works great. Very simple and easy to walk around and get the temps of anything you want to in a few seconds.

 

[GLASMITHS]

My advice is to get the tire sidewall data IE 235/85R-16 E off your tires and go to your tire manufacture's website and put in that tires data and look up the recommended inflation pressure off of the inflation pressure/load chart or table on their website. This combined with actually weighing you truck and trailer on a commercial scale to determine what each (tire if possible) axle is carrying will provide the best recommended pressure. Note that in your owners manual packet there should be a paper from Dodge with recommended pressures for your truck. My 03 DRW 235/80R-17 E's according to Dodge require only 65 PSI for full load. Keep in mind that there is a max inflation pressure on the sidewall that should never be exceeded and that all inflation pressures are cold inflation pressures. In my opinion its better to run a little higher pressure than lower pressure within reason. Also note that in most 3/4 and 1 ton SRW trucks, rear GAWR is frequently limited by tire load capacity at the maximum inflation pressure. IE each tire is rated at 3042# and GAWR is 6084# on my 97. Hope this helps. Ken irwin

#1 there is NOT any maximum pressure stated on the sidewalls of a D rated and above tire. There is a maximum load, but not maximum pressure. When I tow there is 90psi in all tires. This eliminates all the guess work about weights and charts and the like. Several years ago Trailer Life had an indepth article that had extensive input from Michelin and Goodyear. Their recommendation was to run up to 10 psi above the sidewall pressure that way you will not be under pressure. They also stated that if you ever run the tire under inflated, it is not IF it will fail but WHEN. Because most all tire failures are caused from initial under inflation, that causes the tire to heat up and blow. Unloaded I run 65psi all around. Loaded I ran 26K around South Texas 110+ temps in summer. Got 58K out of OEM Michelin tires. Must not be too bad on'um. :-laf

 

[Larv]

Looking at the data on the door pillar I think I'll run 60 in front and 70 in rear... ... . Larv

 

[BigMike]

#1 there is NOT any maximum pressure stated on the sidewalls of a D rated and above tire. There is a maximum load, but not maximum pressure. When I tow there is 90psi in all tires. This eliminates all the guess work about weights and charts and the like. Several years ago Trailer Life had an indepth article that had extensive input from Michelin and Goodyear. Their recommendation was to run up to 10 psi above the sidewall pressure that way you will not be under pressure. They also stated that if you ever run the tire under inflated, it is not IF it will fail but WHEN. Because most all tire failures are caused from initial under inflation, that causes the tire to heat up and blow. Unloaded I run 65psi all around. Loaded I ran 26K around South Texas 110+ temps in summer. Got 58K out of OEM Michelin tires. Must not be too bad on'um. :-laf

My E rated tire sidewall says 80psi max.

 

[GLASMITHS]

My E rated tire sidewall says 80psi max.

Am not sure what brand of tire you have, but my 2 new Michelins on the front and Goodyears on the back say "Max WEIGHT at 80 psi"

 

[JBlock]

Those temperature guns are real cool.

 

[bombero]

Jees. now that I learned that I can put more pressure in my tires I need to buy a new air compressor. Mine only goes up to 125lbs

 

[PatrickCampbell]

Really interesting about what you say RE: Max pressure. vs max load. Can you provide a link to the article?

 

[Kirwin]

Max pressure and Max load

GLASMITHS I have to disagree with you. From Michelins website under the XPS Ribs tires there is a note that you should never exceed the max pressure as branded on the sidewall of the tire. Now you may be able to argue that the tire is not branded "max load at 80 psi MAX pressure". However the weight VS inflation pressure chart for all E rated 235/85R-16 tires stops at 80 psig 3042 lbs max load single. I agree with you that generally a tire is better to be over inflated for the load than under inflated but a substantially overinflated tire will also be damaged by the excessive stresses associated with over inflation. All tires fail in some manner if ran long enough. The goal is for the tread to wear out before the tire breaks down and fails by some other method such as tread separation or belt shift in the casing of the tire. Ken Irwin

 

[R-N-R]

Michelin 265s are rated for max 80psi. Towing a 6500# TT at max psi in all 4 resulted in a sway condition, and I have a sway control hitch! I run empty at 55psi to help smooth out the ride, towing I use 65psi in the front and 70psi in the rear.

 

[GLASMITHS]

Really interesting about what you say RE: Max pressure. vs max load. Can you provide a link to the article?

No link. If I lived in AZ I would run the amount on the sidwall for safety alone. To a point, the tire will run cooler the more it is inflated. Am not sure what the effect will be for the guy with the 125 psi compressor. Maybe like a blimp. Ask Barry the MOD about tire pressures. The factory gives you the minimum pressures, taking inconsideration ride quality. Safety is my biggest concern.

 

[Grizzly]

When you leave home, go thru Oregon. All the chickencoops leave the scales on.

Weigh the truck and trailer, axle by axle and use the chart that came with the truck to determine the correct pressure. My 2002 Ram 3500 towing a 13,000 5th wheel takes 50-55 in the front tires and a max of 40 in the duallys. the trailer can also be checked this way.

I believe you may be under inflating. With a diesel, you should have no less then 60 psi on the front all the time and with as much load as you have I would have no less then 50psi on the duallys. Look at the chart on the door post. Grizzly