Tire Pressure (Max or not to Max) Experts?

[FlyingDiver]

Originally Posted by NeilV

With the tires at max you do all of the above and chance loss of control on rough roads. Max out a tire to 120 on a load that only requires 65 and you can find your wheels dribbling like basketballs after a chatter bump and taking you right off the outside of the next turn in the road.

I used to have a car that did that. A '69 Mustang Mach One. It was so front-heavy that the rear end would break loose at the slightest provocation. Fun to drive though, as long as you were going fairly straight.

joe

[georgetown350]

Batman the max load stamped on the tire has nothing to do with the max load for your rig. Example... our rig tires are stamped 120 max and the recomended max inflation for maximum load is 90 psi..... so if you want to go max why not go max recomended by manufacturer of rig? I once tried max 120 and I thought the tv was going to rattle out and fall on my head the ride was so rough.

[mythplaced]

Originally Posted by Algoma

.....?

4. I don't think RV owners have a phobia about tires anymore than car and truck drivers. RV tires don't wear out they just die of old age which is the major difference.

....

I have that phobia! I know I can handle wrestling a car safely to the shoulder of the road after a steering time blowout at 70mph (been there a couple times)

I'm not so sure the outcome would be as easy or forgiving if I lost a steering tire on the MOHO at 70mph.....

[DriVer]

Originally Posted by mythplaced

I'm not so sure the outcome would be as easy or forgiving if I lost a steering tire on the MOHO at 70mph.....

Michelin has a video that instructs the driver to hammer down in the event of a front tire blowout and then pull over to the side of the road and back out of the gas. The entire operation requires the driver stay off the brake pedal.

[Tom N]

Originally Posted by Batman_777

It was not clear if there is a safety or equipment concern when running tire pressure at the sidewall max.

(1) Why not keep the tires inflated at the max per load pressure on the sidewall? That way, I know I'm good up to the tire's max load. You might run a little stiff, but the peace of mind outweighs the ride softness.

Do we have any absolute answers?

I consider Michelin's RV Tire Guide as the "absolute answer" to Maximum inflation, and I'll quote that publication below.

"Overinflation, on the other hand, will reduce the tire’s contact area with the road, which reduces traction, braking ability, and handling. A tire that’s overinflated for the weight it’s carrying is more prone to a harsh ride, uneven tire wear, and impact damage."

-Tom

[Always-RVing]

A man parked next to me in the RV Park has experienced 3 (Three) blowouts. Both front tires and one inner rear. Zipper cuts along the sidewall appears to be the cause. He said watch your tires for small cuts high on the sidewall close to where the tread meets the sidewall. Of course, that would be difficult for the dually inside tires and checking the inside sidewalls would be painful. In all three cases, he said the blowouts were due to tire defects. Goodyear G670 are the tires he is presently using. I'm not sure what the tire manufacture was for the 3 blowouts since this is not his first MH or first set of tires.

4 weeks ago, a man pulled in with a millon $$$ dollar Newel. The right front tire blew and caused some damage to his MH under the wheel-well. In some blowout cases, the front end-cap has to be replaced. The cost is $25,000...

Why are were willing to sacrifice safety for a cushion ride on tires that was aired up marshmellows? I'd rather have a large margin of safety anyday over soft Caddy ride.

The Mgr. @ Discount tire on Hiway 528, Albuquerque, NM said he once saw 20 blowouts in a single day. All were RV, travel-trailer, cargo trailer etc.

It appears that the vehicle manufactures are placing tires on that are close to the load limits to save on vehicle cost. Well, now that does add up. They are allowing for a 10% margin or tolerance. That's not a lot of window to stay within. It also places the burden on the consumer to maintain close strict requirements.

[Ray,IN]

We are discussing two different topics. One:Motor homes should use tire inflation/load tables as a guide, keeping in mind EVERY one of these tables state somewhere in fine print that this is the MINIMUM acceptable pressure for the corresponding load, not the optimum.

Two: towables with ST "special trailer" tires are completely different. They should be operated at maximum sidewall pressure acccording to manufacturers. For instance, Carlisle Tire Inc. states in their warranty that if their ST tires are operated at less than sidewall maximum the warranty is void.

[FlyingDiver]

Originally Posted by Ray,IN

We are discussing two different topics. One:Motor homes should use tire inflation/load tables as a guide, keeping in mind EVERY one of these tables state somewhere in fine print that this is the MINIMUM acceptable pressure for the corresponding load, not the optimum.

The Michelin brochure does not have any such fine print. What it does say is:

For RV use only, Michelin displays tire loads per axle end in the load and inflation tables, as we recommend weighing each axle end separately and using the heaviest end weight to determine the axle's cold inflation tire pressure. For control of your RV, it is critical the tire pressures are the same across an axle, while NEVER exceeding the maximum air pressure limit stamped on the wheels.

To select the proper load and inflation table, locate your tire size in the following pages, then match your tire's sidewall markings to the table with the same sidewall markings. If your tire's sidewall markings do not match any table listed, please contact your Michelin dealer for the applicable load and inflation table.

Industry load and inflation standards are in a constant state of change, and Michelin continually updates its product information to reflect these changes. Printed material may not reflect the latest load and inflation standards.

All their documentation refers to using the "correct" pressure for your weight. No where does it say that the chart value is the "minimum" pressure for the weight.

joe

[melvonnar]

All these posts are great and will keep you busy into the night adjusting tire pressure if your traveling cross country; ( up in the mountains its cold ) adjust your pressure; next day down off the mountain; adjust your pressure; gas up 80 gallons of gas =appx 600# ; fill up water tank 80 gallons; another approx 600# ( adjust tire pressure again) get the message here?
Blow a tire, call michelim; there reply will be one of the following:
too much tire pressure
not enough tire pressure
did you weigh your rig before you blew the tire?
did you weigh your rig after you blew the tire?
you ran over something
riding to close to the edge of the road
back roads have high centers and put the weight on the inner dual
and on and on and on
ask me how I know? answer; been there done that. this is true on just about any tire mfg, not just michelum.
I've traveled over 500,000 miles in motorhomes and have blown my share of tires, I don't even try any more to get warrenty on a tire I've blown.
carry a spare and have road insurance ( trust me you won't regret it)
The side walls on my tires say 95# for max load thats what I carry; there was a time that I went through the weigh the motorhome and adjust the tire pressure; didn't seem to make any difference; The tires still blew and when on a rough road the motorhome would still shake like its comming apart.

[Dmiles]

My head hurts...

[BryanL]

good point! - "We are discussing two different topics." ST trailer tires and motor home tires are indeed two different topics.

for those into "absolutes" and some manufacturer's fine print - relax a bit, will ya'?

re "My head hurts..." -- don't think so much! it really isn't that big a deal. The concept is simple. When it comes to tire pressure, err on the high side. That's all.

[melvonnar]

Originally Posted by BryanL

good point! - "We are discussing two different topics." ST trailer tires and motor home tires are indeed two different topics.

for those into "absolutes" and some manufacturer's fine print - relax a bit, will ya'?

re "My head hurts..." -- don't think so much! it really isn't that big a deal. The concept is simple. When it comes to tire pressure, err on the high side. That's all.

agreed---------just pump those suckers up and hit the road.

[Ray,IN]

Joe, I cannot post a link to mfgrs. information. I do have a lot of bookmarked websites on my desktop that are not on my laptop. I'll have to investigate when we return to the stixNbrix. From searching for a few minutes, it appears Michlen has changed many webpages and pdf downloads on their website.
I will say that the Rubber Industry says over 90% of all tire failures are a result of under-inflation.

[FlyingDiver]

Originally Posted by Ray,IN

I will say that the Rubber Industry says over 90% of all tire failures are a result of under-inflation.

Oh, I believe that. I just don't believe that over-inflation is a good idea either.

joe