Tire Safety

[Gil_J]

Tires are likely the most critical safety items on our coaches that we have control of. Yet, some don't place enough emphasis on maintaining their tires.

Overweight or under inflation are the number one causes for premature tire failure. Do you know the wheel position weight of your tires? If you don't you can't really determine what the minimum air pressure for your tires should be. The tires that share an axle should be inflated to the same pressure. The minimum pressure for all tires on a given axle will be set to the weight of the heaviest side of the axle.

Our tires are speed rated for 75mph and everyone should be driving at less than 75mph. If you exceed 75mph your tires may fail. The failure will likely be due to insufficient pressure for the speed. Here's an interesting article on speed and truck tires (CLICK HERE)

For those that haven't experienced a rapid air loss in a tire, there's a natural fear of a front tire blowout. This video may put your fears to rest (CLICK HERE for Video).

[Joe Camper]

I have a question for those with tire pressure sensors with temp sensing in on them along with pressure.

What kind of temp increases and just what is the temp at 70mph when it's 90 + outside?

[travelite]

Joe,

For many years I ran PressurePro's on my Wanderlodge LXi which had eight Michelin 315's. The steer tires typically increased in pressure from 100 psi (cold at ambient) to 110 psi (hot while traveling 65mph down the highway). This equates to a temperature increase of 50 deg F. If ambient was 70 deg my tire warmed up to 120 deg F. If ambient was 90 deg the tire warmed up to 140 deg F. Pressures increased by 10 psi which is what you'd expect; i.e., theory says you should see a 2% pressure increase for every 10 deg increase in temp.

My Prevost H345 has 365's on the steer and tag, but I'm not running any TPMS, so I have no insight into how the 365's behave. Judging from my IR Thermometer and rest-stop pressure readings they look to run about the same as my LXi's 315's.

[Gil_J]

Michelin says a 10-15 psi increase from cold to driving is typical. I've seen closer to 20 psi at the extreme. I bet anyone crossing death valley today, at 130 degrees, will be testing their tires.

[Joe Camper]

Pressure increases r more than that. My pressure pro used to measure 20 25lb increases on really hot days.

I also noticed how quickly they come down too. As u hit exit ramps if u monitor pressure just prior to pulling Into a rest area they r down by half the amount by the time u get parked and set the brakes.

I'm curious about what temperatures r on a hot day.

A heat gun after stopping is not a real good representation of temps rolling down the road either, if they drop as quickly as pressures do.

Gill IMHO anyone going across death valley during a 130 degree day, unless in an extreme emergency would be just plain dumb. If u need to get across go at night.

The only time I came across death valley was a trip back from Pendleton to Chicago in a 73 Cuda with a cam and a gear. It was the middle of the night and I just barley got through without overheating.

[GoneCrazy]

After learning about Steer tire blowouts and how serious they can be. I opted to have the Tyron safety system installed on My new steer tires. I had to sacrifice some of My bling upgrades like LED marker lights had to go on the back burner. But they can come later. At least now I have a comfort level should I ever have a incident. I also have the new TPMS pulse to monitor and detect a problem before it occurs. The Tyron's are expensive , But just a drop in the bucket in the whole scope of owning and maintaining one of these elegant beasts !

[travelite]

Pressure increases r more than that. My pressure pro used to measure 20 25lb increases on really hot days.

If you really control for all the factors like increases in ambient throughout the day, direct sunlight, inclement weather, and changes in altitude you'll see 10 to 15 psi increases. All of these confounding factors can add to the increase. I used to do my testing at night time on flat ground in the dry. I wanted to isolate the temperature and pressure increase strictly due to the tire warming up. 10 to 15 psi is it, and in my case it was 10 psi increase and a 50 degree F. increase for a warmed up tire

[TheGadgetGuru]

I have a question for those with tire pressure sensors with temp sensing in on them along with pressure.

What kind of temp increases and just what is the temp at 70mph when it's 90 + outside?

Hi Joe,

I'll be reunited with my coach after the holiday and I'll be happy to check that temperature for you. However, the Prevost TPMS is placed at an angle where it's not that easy to read the small numbers while driving as it's prone to glare. So, if I can do it safely, I'll try to remember to do it for you.