trailer tire psi?

[danfinn]

Mine are currently set at 32psi which looks about right judging on the shape of the tires. This is a single axle trail-rite trailer carrying a 19' cuddy. I noticed yesterday that the label on the sticker, the same one that has the VIN, says the tires should be inflated to 50psi.

What should my trailer tires be inflated to?

 

[83Evinrude]

Re: trailer tire psi?

I would inflate the tires to the maximum pressure shown on the tires. Do this when the tires are cold meaning you haven't pulled the trailer that day and the tires haven't set out in the hot sun either.

The max pressure shown on the tires may not match what the sticker on the trailer shows if the tires have been replaced.

 

[robert graham]

Re: trailer tire psi?

a trailer tire, bias belted or radial, is a different animal altogether from an automobile tire. the trailer tires require more air pressure to prevent sidewall flexing, overheating and failure. my tires call for 50PSI, which is what I run.

 

[Silvertip]

Re: trailer tire psi?

The GVWR (gross vehicle weight rating) or load capacity of the trailer is based on the tires originally supplied with the trailer and at their maximum inflation pressure. If you are running with about 2/3 the air pressure required you have essentially overloaded the tires. Their load capacity is based on maximum inflation pressure and most trailers are loaded to 75% or more of the GVWR. Inflate them to the pressure indicated on the sidewall of the tire and check pressure often.

 

[salty87]

Re: trailer tire psi?

what the tire says to inflate it to

 

[SS194]

Re: trailer tire psi?

Wow, I wish I researched this before I went on my trip to Lake Norman. 3 hours each way. I brought the tires up to about 35 psi hot, thinking that would be OK. The tires were much warmer after a long drive than I expected, i guess because they were under inflated.

I'm glad I didn't have a blow out.

Steve

 

[rentprop1]

Re: trailer tire psi?

my question is the side of the tire usually indicates ( example : 50 psi cold at max weight of xxx lbs )

you are never really running near the max weight cap on the tires, so why would you inflate your tires to the full 50 psi ????

I always back it off a few lbs for safety sake.

 

[Silvertip]

Re: trailer tire psi?

So why NOT run them at max sidewall pressure. Most people would be really surprised if they actually weighed their boat trailers when it was loaded with all the stuff they take with them. As I pointed out, most single axle boat trailers get loaded pretty darn close to the GVWR. Anything less than maximum pressure and you are flirting with tire failure. Flexing creates heat. Even your tow vehicle tires should be aired up a bit from their recommended pressure when towing a trailer or hauling a heavy load. That's why two pressures are generally indicated on the inflation tag.

 

[Navy Jr.]

Re: trailer tire psi?

my question is the side of the tire usually indicates ( example : 50 psi cold at max weight of xxx lbs )

you are never really running near the max weight cap on the tires, so why would you inflate your tires to the full 50 psi ????

I always back it off a few lbs for safety sake.

This has been my understanding for years. The same tire brand and model is manufactured for a variety of different vehicles, all with different weights. The tire pressure on the sidewall indicates how much load the tire can handle, and what PSI the tire should be to support that load. Overinflating the tires can result in less rubber on the road, and that can affect handling and braking.

My 4Runner tires say on the sidewall the max load is 2271 lbs and 44 PSI, but the label inside the door jamb says the pressure should be 32 PSI. I set them to 36 PSI for towing.

Our radial trailer tires say 50 PSI at max load of 1850 lbs. In other words, if we are hauling 1850 lbs on each tire (3700 lbs total for two tires in our case), we should set the pressure to 50 PSI. But we are hauling less than that amount (approx. 2800 lbs total over two tires), so we run with less pressure. Our dealer set the tire pressure to 40 PSI. After two 500 mile trips and numerous local outings, the tires are doing just fine. -Ken

 

[Gary H NC]

Re: trailer tire psi?

Believe me guys,Run them at the max pressure as rated on the tire.
Even 10 psi under inflated will heat the tires up and puts major stress on the side walls.
They will blow out and usually it does damage to the trailer or fenders and possibly the boat.
I have had tires blow on car hauler trailers and it blew a hole right through the diamond plate floor.Imagine what it would do to fiberglass.

 

[highN'dry]

Re: trailer tire psi?

With a trailer tire, if the sidewall says 50 then you should be at 50 psi.

 

[virgil47]

Re: trailer tire psi?

I believe that over inflating a trailer tire can lead to severe handling problems. If your tires are over inflated it promotes wheel hop or bouncing and skipping of your boat trailer. Air born trailers do not respond well to directional inputs. Please figure out the approximate load on your trailer tires and inflate accordingly.

 

[4JawChuck]

Re: trailer tire psi?

I sent an e-mail to Carlisle asking this question last year as I found conflicting info on the internet, they told me 50psi at all times.

The reason the e-mail said was trailer tires need the support in the sidewalls and lower inflation pressures could cause sway and sidewall blowout at highway speeds. After inflating mine to 50 psi (I was running 35psi) it sure handled nicer on the highway and just putting my hands on the tire after towing for a long distance you could feel they were running cooler...a lot cooler.

If your just towing to the dock and back inside town or the city 35 psi might be OK but highway speeds require max inflation pressure, try it for yourself and see!

 

[Navy Jr.]

Re: trailer tire psi?

Ok, I'm about ready to walk away from this one, but not before one more crack at it.

First, Carlisle is a manufacturer of heavy construction equipment. Their loads, by definition, are on the high side.

The load rating on the sidewall of recreational trailer tires represents the highest weight the tire was built to handle. The PSI on the sidewall represents what the pressure should be if you were to carry that weight on that tire. If you are indeed carrying the max weight for the tire, you need the max pressure to keep the proper footprint of the tire on the road. Too little air results in the sides of the tire carrying most of the load while the center doesn't carry enough. That's where the sidewall flexing and overheating come into play.

If you carry less weight on that particularly rated tire, you need to adjust the air pressure accordingly, again to keep the proper footprint on the road. If you max out the pressure to 50 psi on a much lighter load, you run the risk of the center of the tire being more on the road than the sides. Sure, the sidewalls won't flex as much and the tires will run cooler, but the tires won't be performing the way they are meant to. As someone above mentioned, you'll get wheel hop; and I will add that they won't track well in wet weather, and, if you have them, your trailer brakes will be less effective.

I agree that in the OP's case 32 psi is more than likely too low. It all depends on the weight of his rig. He needs to know what that is before he can reasonably determine how much pressure to inflate his tires. If the weight is indeed at the max load rating of his tires, then, by all means, set the pressure to 50 psi. -Ken

 

[Gary H NC]

Re: trailer tire psi?

Think about this....
Do tractor trailers that carry 45K pounds in the trailer let air out of the tires when they run empty?...No they do not.
They run 110 psi no matter how much weight they are hauling because the tires are rated for that amount.

You could weigh the boat and trailer and play with air pressure if it makes you feel better.
I have run 50 psi in my travel trailer,boat trailer and my car haulers with never an issue of wheel hop or wearing the center of the tread.

 

[bruceb58]

Re: trailer tire psi?

Air born trailers do not respond well to directional inputs.

Last time I looked, trailers had no means of providing directional inputs to their tires.

On the serious side, the reason automotive tires run at reduced inflation compared to the sidewall max PSI has more to do with handling characteristics of the auto with varying PSI in the tires. Some cars handle and ride better at a reduced PSI yet still have enough margin for safety in load rating at the reduced PSI. Trailers don't have the same problems as cars in that they just travel in a straight line and the tires aren't steering. Tire hop? I run my tires at max PSI, my tires are loaded at 70% of max load. I have never experienced tire hop. Maybe its because I have a tandem trailer and both wheels would have to hop.

 

[Bifflefan]

Re: trailer tire psi?

a trailer tire, bias belted or radial, is a different animal altogether from an automobile tire. the trailer tires require more air pressure to prevent sidewall flexing, overheating and failure. my tires call for 50PSI, which is what I run.

Very, very inteligent and correct answer.

you are never really running near the max weight cap on the tires, so why would you inflate your tires to the full 50 psi ????

I always back it off a few lbs for safety sake.

Very WRONG answer. the biggest cause of tire is under inflation.

 

[RoyR]

Re: trailer tire psi?

It's the constant increase/decrease in air pressure that heats up the air inside the tire, eventually causing it to fail. Fill it to pressure indicated on the tire...

 

[allinmygarage]

Re: trailer tire psi?

I am in no way a "great tire mind" but I'll throw in my .02 cents. I just bought (2 weeks ago) new tires for my trailer. The service guy at Discount Tire Co. told me to keep them at Max (50psi) at all times. He also said the #1 reason trailer tires fail is due to under inflation. I am in no way saying Discount Tire guy is the bible of tires but I figure they warrantee the tires so they probably are going to tell me the right thing.

I think the word max is deceiving anyway. People hear max and think "keep it under max" or "running at max all the time will wear it down quicker"

 

[Gary H NC]

Re: trailer tire psi?

I am in no way a "great tire mind" but I'll throw in my .02 cents. I just bought (2 weeks ago) new tires for my trailer. The service guy at Discount Tire Co. told me to keep them at Max (50psi) at all times. He also said the #1 reason trailer tires fail is due to under inflation. I am in no way saying Discount Tire guy is the bible of tires but I figure they warrantee the tires so they probably are going to tell me the right thing.

I think the word max is deceiving anyway. People hear max and think "keep it under max" or "running at max all the time will wear it down quicker"

The Discount Tire guy is correct. I have pulled trailers all my life and the number 1 reason for failure is under inflation.
I had 2 out of 4 tires blow out in one day in Nevada....They were just put on in Utah and the place that installed them did not inflate them to the max rating.Between the 110* heat and under inflation it popped those new tires like nothing.
Bought 2 more tires and aired up all 4 to max rating and had no problems for the next 20,000 miles.
I learned to never trust that someone else put the correct amount of air in them.