What tire pressure should I run on my trailer?

[JMT]

I pull a 5x11 trailer behind my TJ pretty often. It weighs 750lb unloaded. What tire pressure should I run on the trailer? Does it change with the amount of load (I'm assuming it does)? E-Trailer recommended running them at the maximum pressure. That just doesn't sound right to me.

 

[bobthetj03]

I have a 4X8 Carson utility trailer I pull on occasion for dump runs, gravel, lumber etc. I'll usually adjust per load, but I never run the max load pressure.

 

[CaliSteve]

I have a 30' travel trailer, a car carrier for the jeep and a small box trailer for odds and ends. I run max pressure on all of them all the time. After I blew out some tires on the TT due to running what I thought would be a soft ride at 35 PSI for the trailer cost me a few thousand in repairs. All the tire shops I've talked to recommend max pressure on trailer tires.
My 02....

 

[Steel City 06]

Rules for trailer tire pressure are similar to passenger tire pressures.

It is perfectly fine to run them at the max pressure. Max pressure is where you will get the best fuel economy and cornering stiffness, which slightly improves trailer stability. However, there will be more vibration transmitted to the trailer.

Look at the max pressure and max tire load. You can scale them proportionally to the actual tire load. E.g, a tire with a max pressure of 50 psi and max load of 1000 lbs, if run at 500 lbs load can be inflated between 25 and 50 psi. Personally I would run at 40 psi in that case. Higher pressure is generally better, but it can be reduced in certain circumstances.

Higher pressure also reduces the risk of blowouts.

The only advantages to reduced tire pressure on the trailer are increased trailer braking performance (on brakes trailers with a properly set up trailer brake controller) and less vibration transmitted to the load. Some types of tires may also see wear benefits from reduced pressures at reduced loads.

Personally I would run them at the max or close to the max. The increased braking capacity is marginal.

 

[JMT]

Very helpful to all. I raised my pressure from 36 to 45, max is 50. Thank you for the good advice and pros, cons, warnings

 

[Farmergreg]

Sidewall flexing creates the heat. Keeping them at max prevents minimizes the flex.

Was reading where someone with a motorhome asked about dropping the initial cold pressure when driving in the "heat" like arizona in the summer. Their thinking was the initial cold pressure equated to too high of PSI when warmed up on the hot roads. Truckers responded saying they would run higher initial cold pressures when driving in the heat.

 

[JMT]

Sidewall flexing creates the heat. Keeping them at max prevents minimizes the flex.

Was reading where someone with a motorhome asked about dropping the initial cold pressure when driving in the "heat" like arizona in the summer. Their thinking was the initial cold pressure equated to too high of PSI when warmed up on the hot roads. Truckers responded saying they would run higher initial cold pressures when driving in the heat.

That seems counterintuitive. Interesting. I’d have to think that one through. I’m not sure our tires heat up that much when we drive. Maybe 5-7psi max?

 

[Farmergreg]

That seems counterintuitive. Interesting. I’d have to think that one through. I’m not sure our tires heat up that much when we drive. Maybe 5-7psi max?

I've got a 5th wheel camper. Set 80PSI cold on the rear truck tires (max load cold inflation). When I've checked them they go up about 10% so 87-88psi. Seems like whenever its hooked to the truck its 100º out!

on edit: I'll have to monitor it more now that I have a truck TPMS.

 

[mrblaine]

I have a 30' travel trailer, a car carrier for the jeep and a small box trailer for odds and ends. I run max pressure on all of them all the time. After I blew out some tires on the TT due to running what I thought would be a soft ride at 35 PSI for the trailer cost me a few thousand in repairs. All the tire shops I've talked to recommend max pressure on trailer tires.
My 02....

I've never blown out a trailer tire at max pressure. I have ruined several overheating them at less than max pressure. If the trailer moves, the tires are at max.

 

[mrblaine]

Sidewall flexing creates the heat. Keeping them at max prevents minimizes the flex.

Was reading where someone with a motorhome asked about dropping the initial cold pressure when driving in the "heat" like arizona in the summer. Their thinking was the initial cold pressure equated to too high of PSI when warmed up on the hot roads. Truckers responded saying they would run higher initial cold pressures when driving in the heat.

Tire manufacturers know that tires rise in pressure when they are run from cold to hot. That is accounted for in the cold max pressure rating.

 

[mrblaine]

That seems counterintuitive. Interesting. I’d have to think that one through. I’m not sure our tires heat up that much when we drive. Maybe 5-7psi max?

Proportionally perhaps, but we will leave camp at 8 psi. At the trailhead we check again and the pressure has gone up 2-3 psi. That is a 25-30% increase in pressure. It is never less than 2, sometimes as high as 5. Pressure is equal to temperature x volume. Since the volume doesn't change, pressure will rise with an increase in temp and the hotter it gets, the higher it will rise.

 

[qslim]

I pull the TJ and various other contraptions on a, 18' car carrier. I've always run max tire pressure (50psi), have never had a blow out, and have always had even tread wear on all 4 tires

 

[Steel City 06]

Higher tire pressure equates to cooler tire temperatures and reduces the risk of blowouts. Not only does the reduced sidewall flex generate less heat, the additional air pressure helps to convect the heat away from the tread and sidewall.

The Ford Exploder / Firestone case is a great example of how reduced tire pressures yield more blowouts. Ford reduced the tire pressure on the Explorers to increase ride quality, but the reduced tire pressure combined with tire defects resulted in significantly more tire failures, and 271 fatalities in the US alone.

 

[derekmac]

A trailer tire should be run at whatever is listed on the sidewall.

 

[JMT]

I maxed them out at 50 psi. Thanks, good information

 

[ac_]

Just to add, since you know I now have a car hauler, and am going to meet you up in Moab, I have joined a camper forum of which most people that have campers pull trailers, and I asked the same exact question, and they all said run the max on the trailer. So that is what I do also.

 

[JMT]

Just to add, since you know I now have a car hauler, and am going to meet you up in Moab, I have joined a camper forum of which most people that have campers pull trailers, and I asked the same exact question, and they all said run the max on the trailer. So that is what I do also.

Groovy. Thanks for reaching out to another group of DIY professionals for me!