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Old 10-20-2013, 10:08 PM   #41
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Originally Posted by SBTAR View Post
When I had 5000 miles on my solera noticed tire wear on outside edges of front tires had pressure at specs on the door. Since than inflated them to 80psi cold 10,000 miles on them now,tires look perfect now,thought it was alignment problem. Think it was the lower pressure. I think it's safer to run them at the 80 psi because the tires run cooler. You have a little extra weight carrying capacity and you get better gas mileage because the tires roll with less resistance. The only draw back is you get a little harder ride. Does not matter about how much pressure they are when there hot. Manufacture say 80 psi cold so I sure they figured for heat and temperature increase.
I would say your front axle is loaded heavier than the expectation from the mfg. What are your actual loads on each front tire? Bet we find that the load/infl tables suggest somethnig closer to 80 that the placard inflation.
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Old 10-20-2013, 10:08 PM   #42
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Originally Posted by Tireman9 View Post
Bet those tires were bias ply not steel belted radials.

Race car drivers do a lot of things that should not be done for regular highway use.
They were bias ply tires and we also modified the pattern by grooving them for more bite and siped them for cooling.
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Old 10-20-2013, 10:16 PM   #43
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And it also states "Over-inflation tires make for spectacular explosions". Doesn't make any difference how they got over-inflated. I don't deflate hot tires because it is a pita and requires re-inflation, but if someone wants to do it, it won't hurt a thing. To each his own. I have yet to see a tire manufacture warn against deflating hot tires. If I were on a long trip and the temp and pressure kept rising and the pressure got to a point that "I" considered excessive, I would bleed them off. Truck System Technologies(TST) states: "We recommend you set the parameters at 15% above and 10% below what you typically run in your tires. System Technologies believes to be the safe zone. As for temperature, the monitors are preset at 157' F, a safe setting for all tires, which typically fail between 180-200" F."
So, in my case with a 65# cold pressure and the recommended 15% over cold pressure for an alarm, 10# over or 75# would be setting off the alarm and I would deflate.

You might want to read the top of pg 6 of the Michelin RV tire guide

Do I need to find similar from other tire companies?
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Old 10-20-2013, 10:23 PM   #44
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you might want to read the top of pg 6 of the michelin rv tire guide

do i need to find similar from other tire companies?
no page 6
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Old 10-20-2013, 10:28 PM   #45
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A tire's maximum inflation pressure is the highest "cold" inflation pressure that the tire is designed to contain. However the tire's maximum inflation pressure should only be used when called for on the vehicle's tire placard or in the vehicle's owners manual. It is also important to remember that the vehicle's recommended tire inflation pressure is always to be measured and set when the tire is "cold." Cold conditions are defined as early in the morning before the day's ambient temperature, sun's radiant heat or the heat generated while driving have caused the tire pressure to temporarily increase.
For the reasons indicated above, It is also normal to experience "hot" tire pressures that are up to 5 to 6 psi above the tire's recommended "cold" pressure during the day if the vehicle is parked in the sun or has been extensively driven. Therefore, if the vehicle's recommended "cold" inflation pressures correspond with the tire's maximum inflation pressure, it will often appear that too much tire pressure is present. However, this extra "hot" tire pressure is temporary and should NOT be bled off to return the tire pressure to within the maximum inflation pressure value branded on the tire. If the "cold" tire pressure was correctly set initially, the temporary "hot" tire pressure will have returned to the tire's maximum inflation pressure when next measured in "cold" conditions.
A tire's "maximum inflation pressure" may be different that the assigned tire pressure used to rate the tire's "maximum load." For example, while a P-metric sized standard load tire's maximum load is rated at 35 psi, many P-metric sized standard load performance and touring tires are designed to contain up to 44 psi (and are branded on their sidewalls accordingly). This additional range of inflation pressure (in this case, between 36 and 44 psi) has been provided to accommodate any unique handling, high speed and/or rolling resistance requirements determined by the tire and vehicle manufacturers. These unique tire pressures will be identified on the vehicle placard in the vehicle's owner's manual.

Ok lets try and clear up the "Maximum" inflation question.

First all tires have markings identifying the "Maximum" load associated with a "Cold" inflation.

Second, Some tires have a "Safety Warning" that mentions when "mounting" tires you should have a professional do the job and as part of that mounting information safety warning they give a maximum inflation. The reason for this is that if a tire is damaged during mounting or not centered on the wheel before the beads "seat" or the wheel is the wrong size (yep some people make that mistake) we want to prevent an explosion due to improper "seating" pressure against a damaged tire bead.
Once the tire is properly seated the inflation will many times exceed the maximum "seating" pressure but it is OK at that point as the tire is now properly seated on the rim.


If you have questions about I suggest you get a flashlight and sit down and actually read the information on the sidewall of your tires. I did a post just on that topic April 24 2013.
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Old 10-20-2013, 10:38 PM   #46
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We always used nitrogen for aircraft tires for several reasons. Pull the following info. from a web site and it might answer some questions.

First is that nitrogen is less likely to migrate through tire rubber than is oxygen, which means that your tire pressures will remain more stable over the long term. Racers figured out pretty quickly that tires filled with nitrogen rather than air also exhibit less pressure change with temperature swings. That means more consistent inflation pressures during a race as the tires heat up. And when you're tweaking a race car's handling with half-psi changes, that's important.

Passenger cars can also benefit from the more stable pressures. But there's more: Humidity (water) is a Bad Thing to have inside a tire. Water, present as a vapor or even as a liquid in a tire, causes more of a pressure change with temperature swings than dry air does. It also promotes corrosion of the steel or aluminum rim.

How is water relevant to a nitrogen discussion? Any system that delivers pure nitrogen is also going to deliver dry nitrogen. Filling tires with nitrogen involves filling and purging several times in succession, serially diluting the concentration of oxygen in the tire. This will also remove any water.

It's certainly simple, although time-consuming, for a tire technician to fill and bleed tires. But most shops use a machine that not only generates almost pure nitrogen by straining the oxygen out of shop-compressed air, but will also automatically go through several purge cycles unattended. Some shops have been charging as much as $30 per tire for this service. I think that's too much. If you're buying a new tire, it should be far less. Still, the nitrogen generator, filling system and technician's time aren't free—the dealer is entitled to some return for that.

So, to answer your specific questions: With nitrogen, your tire pressures will remain more constant, saving you a small amount in fuel and tire-maintenance costs. There will be less moisture inside your tires, meaning less corrosion on your wheels. You will not be able to feel any difference in the ride or handling or braking, unless your tire pressures were seriously out of spec and changing to nitrogen brought them back to the proper numbers.

If the pressure remain more constant (lower) because you have dryer inflation "gas" how will that get you better fuel economy?
It is well documented that lower pressure increases fuel consumption. This is because lower pressure allows more tire flex which generates heat. Heat generation consumes energy which means it takes more effort from the engine to move the vehicle. More engine effort is lower fuel economy.

Sorry the advertising hype isn't supported here.

I have multiple posts on Nitrogen and on fuel economy. Also You tube videos.
Simply search YouTube on "roger marble tires"
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Old 10-20-2013, 10:41 PM   #47
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Please explain the harm. Extra work I fully understand. If my alarm goes off at 10# excess pressure I just stop and let them cool. TST TPMS recommends 15% over cold pressure as the alarm setting. In my case that's 10#.

Extra work means extra heat. Heat is what kills tires. The damage is microscopic (at first) but never repairs itself.

TPMS are external to the tires so are actually cooled by the air moving around the valve stem. If you have high moisture content your infl will increase more. maybe set the High pressure alert a couple pounds higher.
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Old 10-20-2013, 10:44 PM   #48
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no page 6

sorry Try pg 7

"Never let air out of a hot tire."
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Old 10-20-2013, 10:45 PM   #49
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Hey folks this has been fun but I have to get up early for some out patient surgery. I hope to be back on line by Tuesday.

Roger
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Old 10-20-2013, 10:45 PM   #50
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Originally Posted by Tireman9 View Post
Extra work means extra heat. Heat is what kills tires. The damage is microscopic (at first) but never repairs itself.

TPMS are external to the tires so are actually cooled by the air moving around the valve stem. If you have high moisture content your infl will increase more. maybe set the High pressure alert a couple pounds higher.
The extra work I was referring to is the re-inflating. Temp warning is 157°, but if it gets to 115°, I will be pulling over and letting them cool for a while.
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