Trailer Tire Pressure

[desertryder]

My trailer tires are rated for 80 psi cold.

I usually fill them to 80 psi.

Is that good or bad ?

Trailer 30ft 5th wheel 12000 pounds.

Shold I start out with them at 70 anticipating them heating up?

Or just leave them at 80 and don't woory.



Thanks

 

[keimmmo]

Tire pressures are ALWAYS measured COLD!!! NEVER let air out of a tire because it has "too much pressure" after it has run a while and is hot!



How much pressure you need depends on the load the tire is carrying. If you are near the load limit, run 80 psi. If you want a smoother ride and the tires are not loaded to the limit, you can reduce the pressure. If you go too low, you will know it. The tires will run hot and the trailer will not be stable.



Steve Keim

 

[Foil Freak 1211]

80 PSI, I'm assuming that your tires are load range "E", with a little over 3k capacity. Your tires alone have the ability to carry the entire weight of the trailer. Pin weight is usually less than 20%, so assume 2400 lbs. I personally don't see a reason not to run at max PSI, but given your weight, you should probably be OK at 70 PSI.

 

[desertryder]

thanks for getting back to me.

Leave them at 80 and enjoy my trip to Idaho.

 

[TowPro]

Put the RV on a scale. Take the weight of the RV (just the weight of the RV on the trailer tires) and devide by 4. Now you know the weight on each RV tire. Next go the RV tire manafactures website and look for the chart that shows PSI required for the actual weight on each tire.



Also do the same for the rear tires on the truck.

 

[Hitec.Redneck]

I read an article that was from Goodyear, ( dont have the link) and it discussed this. THey recommended running the tire at the max pressure on the tire to get the max load rating. I used to run my tires at 10 PSI less than max, but since have started running them at 80 PSI now. So far no problems.

 

[DogDiesel]

Radial flex

Tires should not be run low enough serious sidewall flex.

If the tire is warm after a run and you are below max pressure, add air.







Tire manufacturers call for near the max inflation.

I'm a military maintenace guy, and the military has a habit of running too low pressures. Central Tire Inflation Systems, etc. Bad.



Subsequently, I see big tires with ripples in the sidewall. That tire is ruined.



For me, I run at max pressure. No matter the load. Because of this, I normally get the rated tire mileage life or more and smooth wear.



Wayne

 

[TowPro]

Here is the tire load chart from Goodyear.

 

[SnoKing]

According to Michelin customer service, running a tire over inflated makes it more apt to receive impact damage. They recommend following the inflation charts. If you trailer is 12K GVWR, not all of that is on the trailer axles, as the pin weight is on the truck tires. You need to weigh your rig ready to travel. Then use the inflation charts. If you drive fast, that is over 65, then you can add 5-10 lbs more per tire. SNOKING

 

[Foil Freak 1211]

How is running a tire at max pressure over inflated? I've heard of TONS of tires failing because they were under inflated. I haven't heard of a single tire failing due to it being inflated to max PSI.

 

[TRLRTRSH]

Another thing to keep in mind is, Is your trailer riding level, Nose high and the rear tires will have more weight on them. Nose low and the fronts will. Ours does (nose high a bit) and we always have 80 psi in all 4 tires,... have not a any problems yet... knock on wood!!



Bill

 

[SnoKing]

How is running a tire at max pressure over inflated? I've heard of TONS of tires failing because they were under inflated. I haven't heard of a single tire failing due to it being inflated to max PSI.

Based on the inflation chart. SNOKING

 

[klenger]

I run my trailer tires at max 80 lbs, but run the truck at 65 lbs, based on the tire load chart that came with the truck.

 

[TowPro]

How is running a tire at max pressure over inflated? I've heard of TONS of tires failing because they were under inflated. I haven't heard of a single tire failing due to it being inflated to max PSI.

When a tire is over inflated, the contact patch where it contacts the road is smaller. With a smaller contact patch, you have less traction which can cause a slide. also the tires will wear the centers out if over inflated.

Plus an over inflated tire will tend to bounce more then a properly inflated tire.



Most RV's have tires that are at there max load when the RV is at its max load, so running at max PSI is darn near correct. But still check, my Titanium has tires rated to carry much more then the RV weight, so max inflation is over inflated on them.

 

[Foil Freak 1211]

The link above only has "RV Tires" listed. My 5er has 265 75 R 16 LTs. Does that make a difference? My 5er is about 11200 with 1800 pin weight when loaded, I've always run max PSI. I have never experiened loss of traction or a slide with the trailer. I don't tow enough to worry about wearing out the tread on the tires - they always dry rot long before that. I think I'll keep running max PSI.

 

[Bob Cochran]

I agree with Foil Freak 1211 - I have the same thing with my 14,000 5er. The biggest thing I worry about is the flex of the trailer tire side wall when backing. Even at max psi it look like the tires are going to roll off the beads. So max air means the bead is much snugger to the wheel. The trailer manual for my Everest says inflate tires to max PSI.

 

[SnoKing]

I run my trailer tires at max 80 lbs, but run the truck at 65 lbs, based on the tire load chart that came with the truck.

So why do you believe the load chart for your truck, but you do not believe it for your trailer. The lady at Michelin Customer Service says that this MAX AIR is another one of the myths that goes around. My Cardinal weighs around 9K on the axles. At 80 lbs of air, that is over 3K of extra load capacity. The sticker on the trailer states 65 and the Michelin tech put that in them without looking at the sticker. I questioned him and he said that was about right for a trailer that size. The all steel Michelin's are not going to roll off the rims. If one has a 14K 5er with 235/85r16, then you are close to the 12K+ that they carry and the load chart will have you at Max Air.



Negs of running more than the required air:

Reduce contact patch/Reduce Braking

Reduce handling

Increase chance of impact damage

Uneven tire wear

Harsh ride



Both our trailers could get by with D rated tires running 65 lbs of air. Air is what holds run the weight. The same load chart shows the D and E at 65 lbs holding up the same amount of weight.



You have a very good web site, that has helped a lot of people with weight issues. Why not call GY and Mich, and see if they tell you the same thing. I currently do not believe this max air myth, but I am open to new knowledge. Carlylise is one of the few that says to run max air, but I believe that is a bandaid to try to work around their many tire failures. For what it is worth, the GY G's and Mich E are the best tires out there.



SNOKING

 

[klenger]

I run the max air on the trailer tires because the loading on the trailer tires is much closer to the max rating for the tires. For the truck, I'm considerable under the max tire load rating.

 

[SnoKing]

I run the max air on the trailer tires because the loading on the trailer tires is much closer to the max rating for the tires. For the truck, I'm considerable under the max tire load rating.

???



From your own web site, you stay that your actual axle weight is 7450 (maybe you have increased that) and you have your tires at 80LBs which is good for 12168 lbs. That is 4718 excess capacity! 7450 is not close to the 12168 ability of the tires. At 1832 lbs on each tire, you only need 40 lb of air in each tire according to the inflation chart. Now I would not run them that low, but 80 lbs in WAY over inflated in your case. SNOKING

 

[SnoKing]

Klenger, another question, you still using the brake smart controller? I have thought about one. I wonder about reliability now that they are being made again. I know that a few people had issues with the first go round of the units. It is a very good concept. SNOKING