I'm curious - how much tolerance does everyone have for tire pressure?
IE if you're shooting for 115, how much below that does it have to be to make you drag the hose out?
And then - do you overshoot the pressure a bit to give you a little headroom for possibly not having to top off the next day (assuming consecutive travel days)?
I don't see a lot of loss in air pressure. Actually it seems that the tire loses air more if it is setting for a long time. I like to have the pressures close side to side , especially the front tires. I don't overshoot the pressures. They will increase as the tire warms during travel. I run 110 on the fronts and 100 on the rears on the 24.5 inch rims of my non-slide Newell. The suggested pressures on the sidewall are for a "cold" tire.
When traveling day after day I "slap" each tire with a bar to determine if it is soft each day before departing. A hand held infrared thermometer is useful to check tire temps during or at the end of the day when tires are warmest. At a rest stop I sometimes just lay the palm of my hand on each tire to determine if one is hot.
I run my 1992 at 120 front, 110 drive and 100 tag. I try to get them within a pound or two of matching before I leave for a trip. I use an infrared thermometer at rest stops as soon as I stop. The side of the coach on the sunny side will always be hotter during the summer. After you have used the infrared thermometer a number of times, you will be able to determine if you have a pressure problem with any of the tires.
With 365's on the front and 315's on the rear, I run 110 psi all around. I check them before each major trip and find that it is rare that I have to add any air (months). I do not let them get under by 5 lbs. and do not over inflate.
We are running 120 front, 100 drives & 110 tags. Check before major trips now and when the bug hits on shorter trips. I try to remeber it only takes a few minutes to check air pressure before leaving. It can take several hours for roadside assistance to replace a tire when I'm in too big of a hurry to check pressures before leaving. I will admit to "thumping" tires like HooierDaddy sometimes instead of using gauge. I do feel for hot tires on stops. I am considering getting a TPMS to make it easier to make sure pressures & temps are all OK. I have convinced myself that 1 TPMS is cheaper than 1 roadside assist for tire failure, especially if there is collateral damage.
A TPMS is a great idea.
On the subject of pressures, when Tom installed his TPMS, there was a significant difference in the readings of the TPMS and his tire gauge. We checked it with my tire gauge which had been calibrated prior to my buying it a number of years earlier and it was about 1/2 way between the readings of the TPMS and Tom's tire gauge. The TPMS manufacturer claims his units are within, as I recall a pound and a half. My gauge read 3 pounds less than the TPMS and Tom's gauge read 7 pounds less. So the moral of the story is try to get them consistent, don't worry if you are a pound or two over because your gauge likely isn't that accurate anyway.
Yes, TPMS is on my wish list as well.
Very true Michael. I had the '93 weighed once at an Escapees location and the guy checked my el cheapo digital gauge and surprisingly it was within a 1/2 psi of his calibrated gauge! He did show me a box of gauges people left after having him check their gauges.
So like Michael said use the same gauge each time and look for consistency.
Completed my first 2-day trip with the EEZtire TPMS. First, the TPMS pressures were within a couple pounds of my gauge. I set the front tires at 130, Drive at 110, and tag at 100. Surprisingly, pressures during the drive both days rose from 7 to 13 lbs. i was driving during the heat of the afternoon in high 90's temps. is this normal?
Temperatures varied with sunny side about 10 degrees hotter. I don't recall anything over 115 degrees.
Another anomaly I did not expect, but finally figured out, is that my toad left front tire was 2 lbs higher and about 10-15 degrees hotter than the other 3. I thought maybe a brake was dragging, but then figured it out that the coach exhaust is blowing on that wheel.
I originally set the pressure high and low pressure alarms at 10 lbs. each way over and under my standard pressure, but got too many high pressure alarms, so I moved the high pressure to 15lbs above the cold temp pressure.
The plan is to identify a problem before a blowout!
All in all I love the system.
Tires flex going down the road. The flexing generates heat. The softer the tire is and the faster it rotates the more it flexes and the hotter it gets. I normally see 10-15 psi rise during driving. At home I've seen 5-10 psi difference between sunny side and shaded side. On the road my inner dual tires run warmer than outers. So, even if I were to set all my tires the same in a shaded parking spot as soon as I drive in sun at speed the pressures go all kittywampus (that's a tire technical term). The manufacturers know this and this is why we measure them before driving.