Traior tire pressure

JoeWhite · Mar 19, 2012

The pressure should be marked on the tire. If it is not visible - if it was my trailer I would not exceed 40lb.

Squidd · Mar 19, 2012

80 psi is the load rating pressure you should set them to..

The 32 psi "seating" pressure is to "pop" the bead on the rim (when mounting)...after they are seated you fill them to rated pressure...

Benny17441 · Mar 19, 2012

Concur with Squidd to fill to the load rating pressure of 80 psi. A properly inflated tire helps dissipate heat build up while trailering. And yes , that is cold pressure.

monkeybars · Mar 19, 2012

you don't need 80psi if your running 1000pound load on a tire rated c at 1800pound load.

abruzzi · Mar 19, 2012

If the tire lists a load and pressure, that is usually max pressure. If you aren't really near max load, I wouldn't run at max pressure. If you are running radial tires, not overdoing the pressure is more important than if the tires are bias ply, but the short answer is over inflation wears the center of the tread fast, and may be a bit less stable. Under inflation wears the outside of the tread quickly, and can overheat.

Geof

Squidd · Mar 20, 2012

Not on a trailer tire... it's only a 12 X 5.5 which is a very skinny tire to start with, at c range or 6 ply it needs the full air to keep sidewall stiff.. It will run cooler and last longer at the "reccomended" (not max) 80 psi pressure...

Lake Superior Sailor · Mar 20, 2012

I agree with Squidd, use 80 psi , small tires go around 2-3 times faster than car tires so they build up more heat....Dale

SamLust · Mar 20, 2012

Run trailer tires at rated pressure. Period. The end. Over 5 mph add 5 PSI. Lets not over think this.

Rick Webb · Mar 20, 2012

Load vs PSI

If you are running the tires at anything close to the max rating then air them all the way up to the maximum rated PSI. If like my Sunfish trailer the tires are supporting less than half of the max the tire is rated for you can run them at a reduced PSI mine are usually at 40 or 45 rather than 80. Yes the tire will run cooler at 80 but the trailer also bounces down the road like a basketball which is hard on the boat and my nerves.

Your tires give your trailer a capacity of almost 2900# if your are over 2000# I would run them close to the 80 PSI. Those small compressors may not even make it to 60 you will want to take it to somone with a compressor capable of filling it. Make sure when you replace the tires you do not get the C range 480 X 12 tires they are only rated at 990#.

The 32 psi for seating is to keep the tire from blowing off the rim and taking the head off of the guy mounting the tire.

Sail123 · Mar 20, 2012

Re: Trailer tire pressure

If you want cooler tires, ditch the air and put in nitrogen, at the correct max pressure, and forget it. If your tire store does not use nitrogen, they like selling tires more than servicing the needs of the customer. Find a tire dealer that uses nitrogen in all their tires. Someone in your area does.

Crazy Dave Condon · Mar 20, 2012

Generally, the tires will tell you load range and with single axle, you double the load range to give you the maximum weight to be towed. This will include the weight of the boat, motor, gear and trailer. I always have suggested a 10% safety factor. Good example load range of one tire is 1000 pounds doubling that on a single axle should be 1800 total pounds of boat, motor, gear and trailer with a 200 pound safety factor. If going to max load range or over it, there are other tires with higher load ranges.

The next thing I make sure they are not under inflated nor over inflate. I will use for example 80 psi but will put in 75 or 76 PSI range. IF the tires are well under inflated or over inflated, often I had blow outs.

In addition check the grease in the bearings as well with an annual inspection of the bearing assemblies which many folks never

I have nearly trailered boats close to 2 million miles over the years. One way to make sure you are fine with your tires, go 20 miles and pull over. Put your hand on the rim and if there is a slight heat or none, you are fine. If tires and rims are hot, then you have a problem

Crazy dave condon

MrBill_FLL · Mar 21, 2012

and the max pressure is COLD pressure. so they will go higher when run...

on the nitrogen, you actually need to fill, drain, and refill a few times to get 100% nitrogen. (when you seat them, they are half full of air).

mostly you are taking out the ambient water in the tire.

LloydB · Mar 22, 2012

I'm guessing that if the tire is deflated to flat on the bottom with 0psi difference between inside/outside and then inflated to 80psi there would be more than 90% nitrogen at the first time. I think air may be near half nitrogen already and doesn't hold moisture as compressed air does.

monkeybars · Mar 22, 2012

atmosphere is 78% nitrogen already,your wasting your money on the other 22% for the extra nitro.it does nothing for a trailer tire other than it's a slightly larger molecule so your tire leak down rate is less,it's slightly less pressure increase when heated and less oxidation on inside of tire but outside carcess of tire will still dry rot and crack.it's main feature is mainly a fire safety concern for commercial aircraft concerning fires in wheel wells,in a fire when the tire melts there is no sudden addition of oxygen at 35000feet to add to the fuel and heat that already exist,the nitrogen will tend to put the fire out instead.the benefit is for the store owner,an 80dollar bottle of nitro will fill a lot of tires at 5 bucks a pop which makes it a very high profit producer for them,with only very minor advantages for you.

Crazy Dave Condon · Mar 22, 2012

Monkeybars, thank you for that response. I use to be a pilot many years ago and forgot about that. Trailer tire pressure is most important and air is the only way I would go. I have pulled so many boats in my lifetime behind my dooley up to 36 feet on my trailers and seen everything but this nitrogen issue I would never do nor do I know any of the commercial haulers doing that either.

However anything can happen. I had just purchased a new hydraulic state of the art boat trailer designed for sailboats. I had a Hunter 340 on it and the right rear or starboard side of the trailer came off. The tire and rim wieghed appx. 200 pounds and rolled up coming to a stop right at the front door of a DMV office. I went back and fixed that from happening again.

crazy dave

CPseudonym · Mar 23, 2012

monkeybars said:
atmosphere is 78% nitrogen already,your wasting your money on the other 22% for the extra nitro.it does nothing for a trailer tire other than it's a slightly larger molecule so your tire leak down rate is less,it's slightly less pressure increase when heated and less oxidation on inside of tire but outside carcess of tire will still dry rot and crack.it's main feature is mainly a fire safety concern for commercial aircraft concerning fires in wheel wells,in a fire when the tire melts there is no sudden addition of oxygen at 35000feet to add to the fuel and heat that already exist,the nitrogen will tend to put the fire out instead.the benefit is for the store owner,an 80dollar bottle of nitro will fill a lot of tires at 5 bucks a pop which makes it a very high profit producer for them,with only very minor advantages for you.

Couldn't agree more. Snake oil is another name for nitrogen in passenger car/trailer tires. Tire shops make a killing up selling customers to this myth. 78% is more than enough nitrogen and you get it for free every time you breathe.

flynfol · Mar 23, 2012

In airplanes it is used because it wont support combustion. 225 psi and glowing carbon brakes can do some bad things. I had a rejected takeoff at max gross after an engine rollback, the glowing brakes caused the fuse plugs to blow....you wouldn't want O2 blasting against a glowing brake. All four tires had to be rejected/ replaced along with the inner rims.......which are magnesium....yikes. Brakes were still good!

kenn · Mar 23, 2012

worth repeating

Crazy Dave Condon said:
I have nearly trailered boats close to 2 million miles over the years. One way to make sure you are fine with your tires, go 20 miles and pull over. Put your hand on the rim and if there is a slight heat or none, you are fine. If tires and rims are hot, then you have a problem

This is great advice.

If after 10 or 20 highway miles the hub is too hot to touch, you have a bearing problem. One trip we found that one side got warmer than the other, so after that trip we found a blown rear seal. I replaced that seal, cleaned and repacked that bearing, and it went back to being as cool as the other side.

We also like bearing buddies.