Also replaced 7 Carlisles. Brand new tires, too, they had a bad run and wouldn't do anything about them.

As another note, a tire's maximum load carrying capacity is not necessarily at the max pressure.

As another note, if travelling at speed of 66-75mp, Goodyear actually recommends inflating at 10psi over max pressure if the wheel is rated to handle the increased pressure. They released a product service bulletin to that effect.

Any LT or ST tire's max load capacity is met at the max pressure, but a P metric or euro metric is not. That depends on whether it's standard or extra load.

Below is part of that service bulletin.

· Based on industry standards, if tires with the ST designation are used at speeds between 66 and 75 mph,
it is necessary to increase the cold inflation pressures by 10 psi above the recommended pressure for the
load.
o Do not exceed the maximum pressure for the wheel.
o If the maximum pressure for the wheel prohibits the increase of air pressure, then the
maximum speed must be restricted to 65 mph.
o The cold inflation pressure must not exceed 10 psi beyond the inflation specified for the
maximum load of the tire.

How do you find out the maximum wheel pressure?

From the wheel manufacturer, most likely found from your trailer manufacturer.

The wheel info is difficult. I want to replace some wheels and it's hard enough just to get data on offset/back spacing and bolt patterns used (without having to measure myself)

Tires should ALWAYS be inflated to max rating while COLD. Some will say that they under inflate to make up for heat expansion. This is absolutely the WORST thing you can do to a tire.

As a side note, I am 100% sold on Nitrogen fill on all my vehicles and trailers. In very hot climates it is difficult to make tires last due to road heat and expansion beyond what manufacturers design for.
Nitrogen is immune to heat expansion and also is almost void of moisture content. Besides being much (4X) denser than air. Small leaks disappear. If trailering any distances, I would highly recommend Nitrogen as a real tire saver. Dirt cheap at most Big O stores.
Tommy

You guys aren't going to believe this but I got 90,000 miles out of the OEM tires on my '98 blazer by running them at least 10 psi over the max. on the side of the tire.

It has to do with wear, if the tire wears on the shoulders (edges) it is not enough air (no matter what the number on the tire is), if it wears strictly in the middle, too much. By doing this we were able to really push the mileage, replaced them only when tread depth got close to but not showning the wear bars, and to have a little more security in the heavy downpours here.

Got 60,000 miles on a set of michelins that were on my old bug in the 70's as I was too poor a student to be buying tires.

This came from my grandmother (who owned a lot of Caddie's) and would get 30,000 miles from the old bias ply tires back in the day. She said run them things rock hard and you will not be buying a new set very often.) She was from South Georgia and you knew it.

Be prepared for a harsh ride, cause hard tires transmit the jolts to the vehicle, for me it meant that when I saw rough roads and railroad crossings there was no "soft tire" to absorb the shock. And no, the shocks on the blazer are still on it and work perfectly 3 years after we sold it to friends that couldn't be happier with the truck. (we needed a diesel for towing the boat).

On a related topic: If you need to haul your empty trailer any great distance, then you consider reducing the psi so the trailer does not bounce down the highway. You get to decide what is a great distance, and always remember to reinflate the tires before you load the trailer.

Secondly: On multi-axle trailers, check your lug nuts frequently. Tight tire-scrubbing corners can loosen lug nuts, resulting in a wheel exiting the trailer while going down the highway. Hopefully no one gets hurt or worse when that happens.

Nitrogen is not immune to heat expansion. It's a gas like every other gas, so it expands (builds pressure) when heated. It's preferred because the typical lack of contaminents provides for a predictable rate of expansion. Nitrogen molecules are larger than "air" molecules, so nitrogen-filled tires typically experience less psi loss over time, but it's no quick fix for actual leaks.

Not trying to bust balls Tommy, just don't want mis-information out there. I've used nitrogen in tires for over 10 years. I keep a small tank at the house and it doubles as a nice portable tire filler and air tool supply.

32fever, is that a Goodyear bulletin for GY tires, or are they making that recommendation for all brands?

JBoat, what size/brand are the tires? I'm just curious what size is rated at 3950lbs@65psi?

Would you agree that being void of the 21% Oxygen (if properly purged), the tire experiences far less expansion and less heat related damage?
Why do you run it?
I know that almost all my tire problems went away when I went to it. Not to mention my tire life almost doubled on everything I have. Have you seen noticeable improvements?

Perhaps "immune" is the wrong word, How about "much less noticeable than air"?

[
32fever, is that a Goodyear bulletin for GY tires, or are they making that recommendation for all brands?
[/QUOTE]

That is a GY bulletin for Marathons. But, the concept applies to all trailer tires.

Also, remember that the air you put in your tires is 78% Nitrogen. And, if you put 100% Nitrogen in and ever have to "top off" with a regular air station, you'll need to purge the tires with Nitrogen again.