Community Forums

seabee13 · 08-29-2010, 09:00 AM

Heading to Yellowstone via I 90 thru Montana down HWY 191 staying at the KOA at the Western Entrance to Yellowstone and it looks like the elevation will peak out at around 11,000 feet on this leg of our trip. Do I need to worry about the air pressure in my tires at this elvation change???? Currently in Deadwood SD. and checked tire pressure no more than one pound difference than a few days ago in Davenport Iowa. Thanks Seabee13

CarlGeo · 08-29-2010, 09:09 AM

Do not change tire pressure at high or low altitude, or temperature changes. Inflate tires to correct pressure at start of trip and do not add or reduce pressure to compensate for altitude or temperature changes.

nsdienes · 08-29-2010, 09:11 AM

If we assume that the difference in air pressure directly affects tire pressure, then going from sea level (14.7) to 11,000 feet (approx 10 psi) would result in a tire pressure increase by 5 psi. Don't think that's something to worry about.

GaryKD · 08-29-2010, 09:14 AM

Hi seabee13,
If you are a resident and staying at that altitude for a while, I'd say change the PSI. Being a tourist, I do not change PSI because of altitude. The same goes for temperature. If I will be in the area for an extended time, I'd change the PSI due to temperature. If I am in the area for a short period of time, I leave the PSI alone.

rops · 08-29-2010, 12:46 PM

The only air pressure differential you will notice at that altitude will be in your ears.

rops

womps · 08-29-2010, 01:05 PM

I agree with the above posts. But I have read if you have a sleep by # bed in your motorhome you should decrease the air pressure before you drive mountain passes. Is this a myth??

wa8yxm · 08-29-2010, 02:41 PM

I can't tell you how high I've gotten with a little help from my friends (Vortec, Allison and Workhorse) but I can tell you I never changed the tire pressure when I crossed the continental divide. From Detroit to Nebraska past Iowa 80 Truck stop on to whatever road I take to get to Salt Lake City to "The Valley" (Las Vegas) and I never let air out of the tires.

skigramp · 08-29-2010, 08:26 PM

You do not need to adjust the inflation of your tires ... that does not mean that you shouldn't check them

Your sleep number mattress is a different matter ... I suggest you lower the number down (to say 35) if you are going to gain more than 2000 feet in a days travel ..

seabee13 · 08-30-2010, 10:08 AM

Thanks for all the good info. You'll have a great day

Seabee13

Ray,IN · 08-30-2010, 06:04 PM

This explains tire pressure and elevation very well: Tire Tech Information - The Influence of Altitude Changes on Tire Pressure
In fact, that website is an excellent primer for tire education.
If you pressurize your tires to sidewall maximum at sea level, you would have to reach about 35,000 feet elevation before the tire pressure reaches the upper limits of design pressure.
Goodyear says their tires are designed for safe driving at all elevations when inflated to sidewall maximum at sea level also.

AFChap · 08-30-2010, 06:11 PM

Quote:

I have read if you have a sleep by # bed in your motorhome you should decrease the air pressure before you drive mountain passes. Is this a myth??

Yes, that is a myth. When I asked Sleep Number they told me not to worry about it ...that there are valves that prevent the bed from being damaged if there should be enough pressure change to be a problem. We have traveled from below sea level to 18,000 or higher and have never changed the pressure until we tuck in for the night and have to let some air out, or add some, depending on where we are that night from where we were the night before.

RVDude · 08-30-2010, 06:45 PM

Quote:

Originally Posted by AFChap

...We have traveled from below sea level to 18,000 or higher...

Can you tell us where you achieved 18,000++ft with your Sleep Number bed??? I am exceedingly curious....

Highest sort-of-paved-road in the USA is Mount Evans Byway in CO at 14,200ft
Highest genuine paved road in the USA is Trail Ridge in RMNP in CO at 12,100ft
Highest "paved road" in world is debated depending on definition of "paved road" but the Ticlio Pass in the Peruvian Andes (~16,000ft) and the Karakoram Highway in China (~16,000) are generally accepted.
Lowest road in USA is Death Valley Bad Water Basin at -280ft.

Don't worry about your SelectComfort bed popping due to altitude, but it is NO myth that your Sleep Number will be meaningfully different at sea level than it is at 10,000ft.

Quote:

Originally Posted by CarlGeo

Do not change tire pressure at ... temperature changes...

This is absolute BUNK! If you depart sunny Florida at 90F (average) and travel to the frigid Rocky Mountains at 20F (average) you ABSOLUTELY WILL NEED to adjust tire pressure as you'll be meaningfully low (and meaningfully high going the other way).

Tire manufacturer inflation tables give COLD tire pressure which means UNDRIVEN AT THE AMBIENT outdoor temp for the location. Do not get all weird and adjust it for daily temp swings, the tire manufacturers already take that into account.

Ray,IN · 08-30-2010, 07:09 PM

I forgot to include this: Just before we left on our 6 week trip I bought a TST TPMS. I monitored it quite often while driving from our house (738' above sea level) to Calgary, AB then down the West side of Glacier to Yellowstone NP, Custer, SD, then back to IN. I never adjusted tire pressure, just watched it. Set point was 80 psi-sidewall maximum, some mornings psi was 82, some it was 76, depending on outside temperature and altitude. Both 82 and 76 are within the allowable differential. Got a nail in a tire near Great Falls, MT. When I took it to a tire shop for repair , they set psi at 74, saying it was an allowance for pressure increase????

These guys are supposed to know stuff_right

AFChap · 08-30-2010, 07:41 PM

Quote:

where you achieved 18,000++ft

You are right ...I was thinking 12,000. And even that looks like a bit of a stretch if your quotes are all inclusive. I believe NE Yellowstone NP last year was a little under 9,000. Monarch Pass in Colorado is between 11,000 and 12,000. Loveland Pass is closer to 12k. I guess if I want to go higher I'll have to take the MH up Pikes Peak or maybe Mt Ranier ...are there MH style roads up them?? ...somehow I doubt it... whatever ...we have driven the Sleep Number bed pretty much as high as you could in a motorhome and never had a problem not letting air out of it before going upward...