Tire Temperature

[jg053047]

After reading several accounts of misfortune on the road, I was curious as to what you should expect as normal tire temperature if you pull into a rest area and happen to have a digital temp gauge on hand to read. On a recent trip to Norfolk I used my device, and the tires read 107 front and 112 rear. Is that acceptable or not? Outside air temps were around 80 degrees.

[mikev]

Hi, I have been checking mine regularly and those numbers are very similar to what I have found. I think they are pretty normal for the ambient temp you indicated of 80 degrees. However the difference front to back is something our more experienced members might comment on...

[Guest 2driftrs]

Funny you should ask - - we checked temps coming back from the beach recently to get a handle on how well our TST tire monitors reported tire temperature. Outside temp was pushing 90, tire temps ran 120-125. Tire monitor reported temps around 100-105. There's a reason for the discrepancy:

Most after market tire monitors are installed on the valve stem outside the tire. The temperature they report is affected by air passing over the monitor sensor, so is really not related to the tire's tread temperature.

The front tires are almost always cooler than the rear. Generally, the fronts are cooler because they are in an unheated air stream and are loaded less than the rears. The rear tires (especially on front engine rigs) get hotter as they pick up engine and exhaust heat from under the rig.

Our driver side rear inside dual always runs hotter and develops higher pressure than the others, most likely because it gets the most of the heat off the exhaust pipe. In fact, to compensate, I run this tire 3 psi lower than the others at ambient temp so that, under driving conditions, it balances with the other rears.

[wolfe10]

I forwarded this thread to my contact at Michelin. Here is the response:

A tire in operation will heat up until it reaches its equilibrium temperature where the heat being generated equals the heat being dissipated.

The temperature of the tire will increase with an increase in ambient temperature. There is nothing to worry about in the ranges stated, if the temperature gets above 250 degrees F then I would be concerned !

Brett

[jg053047]

Thank you for your responses to my question.

My wife and I are joining ya,ll in Redmond for the rally in August and feel more relieved about the temps.

[coyle.schwab@sbcglobal.net]

I'm a newby - just got our Damon Challenger a few months ago.

We've weighed our coach and adjusted the tires' pressures per Goodyear's tables on their website. On a recent trip through Oklahoma I took several readings of individual tire temps at fuel stops. I used an IR thermometer and "shot" each tire as soon as possible after pulling up to the pump. I was delighted to find that each tire on an axle was very close to the same temp.

The steering axle's tires were about 115 dF and the drive axle's tires were about 130 dF. It was a very warm and sunny day - air temps were in the upper 90s.

[WildBill95]

This is interesting. I also have a Damon Challenger with the TST TPMS. Last week I was returning from a trip and the sensors were reading about 94 F with an outside temperature of 90. I guess the temperature readings are pretty much useless. I guess that also accounts for why the temperature increases when stopped, but not the pressure. I keep the pressure at 80 PSI cold, front and back, and when driving they increase to 90 - 95 PSI. Does this sound about normal?

[wolfe10]

This is interesting. I also have a Damon Challenger with the TST TPMS. Last week I was returning from a trip and the sensors were reading about 94 F with an outside temperature of 90. I guess the temperature readings are pretty much useless. I guess that also accounts for why the temperature increases when stopped, but not the pressure. I keep the pressure at 80 PSI cold, front and back, and when driving they increase to 90 - 95 PSI. Does this sound about normal?

Yes, a PSI increase from cold of 80 to driving PSI of 90-95 sounds normal.

A temperature reading while driving of only 4 degrees F higher than ambient sounds low.

Brett

[Guest 2driftrs]

WildBill, look at my June 23 post. The temp readings are relatively useless.

[gcederholm]

We use the SmarTire system where the sensors are installed inside the tire, banded to the rim. I think we get reasonably accurate pressure and temperature readings that way. In general, we see a 10-12 PSI increase in pressure and a larger increase in temperature, which seems heavily influenced by ambient air temperature and sun exposure. We'll run temperatures of 125-135 up to 80 degrees ambient. One tire maxed out at 156F for a short while on I-20 in Alabama on the sunny side of the coach with ambient temps right around 100F.

The other thing we've noticed is that the inner duals will run slightly warmer than the outer.

George C.

[tireman9]

With a sufficiently accurate IR sensor you might see the approx 50 degree difference between the hot bottom of the tire grooves and the

cooler top of the tread (surface that contacts the road). However the handheld units are not capable of providing this kind of accuracy based on my testing.

Hand held IR is probably reasonable for giving the average over a 1 or 2 square inch circular area of a flat surface but the reading for

surfaces with large temperature differences over very small areas as occur on the tread surface, will be misleading.

How hot is a match when burning? You are holding one end so is the average temperature at all meaningful?

Now having said all that, it doesn’t mean your hand held is of no value. If you always take the temperature on the same part of your tires and

always go in the same direction around your RV and never stop for a chat so you keep the timing constant. You could use a drastic increase as a

warning that you need to do additional investigation such as confirm the inflation.