Tire Pressure

[Lumatic]

Originally Posted by w7ts

My entire life, I have replaced tires only when they show signs of needing to be replaced. The secret is to check them frequently and to know what those signs are.


Ken

Other than tread wear, bulges and checking is there anything else you check for?

I have been told that the tire structure deteriorates from the inside out, like dry rot, which is directly related to age and there is no way to check for it. This seems to have been my experience on a couple of older tires which looked good and blew out apparently inexplicably.

[Ag&Au]

Originally Posted by Lumatic

Other than tread wear, bulges and checking is there anything else you check for?

I have been told that the tire structure deteriorates from the inside out, like dry rot, which is directly related to age and there is no way to check for it. This seems to have been my experience on a couple of older tires which looked good and blew out apparently inexplicably.

That is about what I look for. There other obvious things such as road hazard damage and more than normal scuffing from curbs etc.

I can't dispute what you say, but I have never experienced that. I won't discount the possibility that I have just been lucky. However if that's the case where is my winning power ball ticket.

One other thing to consider is the fact that the evidence of the cause of a blow out is often destroyed by the ensuing damage.

Ken

[Lumatic]

Back too the subject of this thread, tire pressure. If you run a tire at too low a pressure you can cause damage to the structure of the tire that is not apparent. Down the road that tire is more likely to blow out, even if it is reinflated to the proper pressure.

[wvabeer]

Then should I run mine at max tire pressure on the tire?

[wvabeer]

OPPS I found my answer
http://www.airforums.com/forums/f438...html#post31963

[kaylorsan]

I've tried to do the weighing/charts, but have gotten more confused (I'm embarrassed I can't read the charts correctly). I was running the OEM recommendation of 61 PSI (door tag) but was showing signs of under inflation. I'm currently running 65 front and 70 rear with good results to date. Nonetheless, I'd like to dial in pressures based upon my vehicle weight.

Below is the email I wrote to Goodyear. They politely wrote back and said to take it to a tire dealer to discuss.

The charts I'm using can be found here. http://www.goodyearrvtires.com/pdfs/rv_inflation.pdf

Am I reading the charts incorrectly?

-Kaylor

----------
Hello,

I'm trying to figure out the optimal air pressure for my tires, but I'm a bit confused. I've gone thru your charts, but the answers do not seem right (tire pressures too low).

Tire Size - LT 215/85 - SR16

Weights
Front Left - 1907 lbs Right - 1837 lbs
Rear Left (Dually - single axle, 2 tires each side) - 3043 lbs
Rear Righ(Dually ) 2973 lbs

From the charts, front tire pressure would be based on a weight of 1900 lbs for an inflation pressure of 50 PSI (this is below the recommended OEM pressure of 61). At 61PSI, after ~ 5000 miles, I'm showing wear patterns indicitative of under inflation.

For the rears, pressure would be based on 3043/2 = 1521 which would yield inflations around 45 psi. Which again is under the OEM recommendations (Mercedes Benz Sprinter 3500).

Is there someone that I can speak to about this? I'm guessing that I am doing something incorrectly.

[Protagonist]

Originally Posted by kaylorsan

I've tried to do the weighing/charts, but have gotten more confused (I'm embarrassed I can't read the charts correctly). I was running the OEM recommendation of 61 PSI (door tag) but was showing signs of under inflation. I'm currently running 65 front and 70 rear with good results to date. Nonetheless, I'd like to dial in pressures based upon my vehicle weight.

As long as the tires on my Interstate are inflated to 61psi, there is no uneven tread wear after 19 months of use that would indicate under- or over-inflation. When I stop for fuel or at my destination, I put my hand against the sidewalls to check for heat buildup, and the tires are no hotter than the pavement they're sitting on.

The sidewalls may bulge a little bit at the bottom, but that's just a cosmetic issue, not a sign of under-inflation. Most radial tires do that; it's just more noticeable on tires that are heavily loaded as ours are.

If you're getting wear on the edges of the tread but not in the center, indicative of under-inflation, at the recommended 61psi, then I'm not sure why, because that doesn't match my experience.

[graysailor]

I run 65 on all four trailer tires. Too new to evaluate long term effects. I am also getting different readings with different gauges.

[Ag&Au]

Originally Posted by graysailor

I run 65 on all four trailer tires. Too new to evaluate long term effects. I am also getting different readings with different gauges.

If you can find the specs on your tire pressure gauges, check them and you will find the accuracy specs can vary significantly. On top of that, drop a gauge just once and its a whole new ballgame. An accuracy of +/-10% is not uncommon with inexpensive gauges. Using that, 65 psi could be anywhere from 58.5 PSI to 71.5 PSI. The only way to be able trust a gauge, is to buy a quality one, test it periodically against a known accurate one and take very good care of it.

you might find this interesting:

Top Tire pressure gauge Ratings | Tire pressure gauge Buying Guide

Ken

[ZoominC6]

Trailer tires are rated at 65psi in most cases. Speed should not exceed 65mph especially in hot weather and on rough highways. Good luck and happy trails.