What tire pressure for 12 in tandem tires

[slbran]

I have a Fiber Stream trailer with tandem axles and 12 in tires. The trailer weighs about 2500 lbs fully loaded. I think each axle is rated for 1800 lbs. The tires say max pressure is 80 psi. For such a light load I am thinking 80 psi is more than I need and will just add to harsh ride. I am wondering if 60 psi would be enough allowing a little more give and less bounce while towing.
Any thoughts?

Thanks,
Steve

[Jon in AZ]

What's the tire rating?

[Byron Kinnaman]

Originally Posted by slbran

I have a Fiber Stream trailer with tandem axles and 12 in tires. The trailer weighs about 2500 lbs fully loaded. I think each axle is rated for 1800 lbs. The tires say max pressure is 80 psi. For such a light load I am thinking 80 psi is more than I need and will just add to harsh ride. I am wondering if 60 psi would be enough allowing a little more give and less bounce while towing.
Any thoughts?

Thanks,
Steve

You might be old enough to remember the Ford Explorer problems with tire pressure. Look it up.
What is generally recommended by the tire manufactures is use maximum side wall pressure. In your case it would 80psi. Trying to soften the ride by reducing tire pressure is asking for trouble in form of blow outs. The more the side walls flex the hotter the tire gets and eventually it makes a loud noise that you probably won't hear. Might ruin your whole day.

[slbran]

The tires are Load rang C - 475 lbs.

[Jon in AZ]

That doesn't seem right. 475 pounds x 4 tires = 1900 pounds maximum on the tires. If your trailer weighs 2500 pounds, you're probably carrying more than that on both axles combined.

How about the manufacturer and size of the tires?

[slbran]

You are correct Jon. The tires are a little hard to read. It is 475 Kg and 1000+ lbs (can not read clearly).

Size is 5.30 x 12.

[Wayne Collins]

Try looking up the LOAD/INFLATION chart for that type and size of tire.
Maybe the Tire and Rim association handbook.
Goto a scale and get the actual weight on the 4 tires.
Divide by 4, set the air pressure accordingly.

A simple rule of thumb: if you see no bulge in the sidewalls they may have too much air.

[Wayne Collins]

Originally Posted by slbran

You are correct Jon. The tires are a little hard to read. It is 475 Kg and 1000+ lbs (can not read clearly).

Size is 5.30 x 12.

475 kg = 1047 lb.

[bill&sandra]

475 Kg is 1045 Lbs. That is @ 80 psi. The load rating drops very rapidly with lower pressure. Don't try to ease the ride by lowering the pressure, early tire failure is that future. Most trailer mfg tell you to use the tire mfg sidewall inflation info molded into the tire and will tell you what size / rating tire to use (B, C, D, etc).

[Wayne Collins]

Another consideration:
Are the two axles mounted on an equalizer suspension? or separately?
If, the latter, it's possible for all the weight to fall on one axle when going over humps or dips. If so, I will bow to the max pressure folks.

[slbran]

Mine does have the equalizer between the springs.