It’s also interesting to think about the fact that the rolling resistance of tires uses a lot of engine energy (hence why it lowers fuel economy), and that much of that energy is converted to heat within the tire itself as it flexes with each revolution.
Anyway, at steady state (after a few hours or less of driving when tire temperatures level off) heat generated within tire must travel to outer surface of tire so it can transfer to the surrounding air, road, etc. I would expect some heat is transferred to air inside tire, which can then transfer to rim (assuming rim isn’t already warmer due to heat from brakes). In any case I would expect that this transfer of heat to inside of tire is minimal, and that that would make the inside surface of the tire, and also the air inside, to be as warm as any part of the tire.
My point in this long post is to say that while the outside temperature of the tire can be felt by touching or measured with instruments, it doesn’t necessarily tell us just how hot the inside of the tire may be. It’s very likely that it’s a lot warmer.
We’d also have to guess that thicker heavier-duty truck and RV tires could have a much greater temperature difference between inside and outer surfaces once steady state is reached.
Also, while on subject of dumb and time-wasting things to think about, it’s also interesting to contemplate that large RV tires have less surface area for cooling relative to the weight they carry compared to car tires. This along with thicker tire that should have greater resistance to heat transfer may explain why RV tire pressures and temperatures increase much higher than in typical auto applications.
For me all this makes a great case for smaller and lighter RVs with smaller tires that run with less pressure.
Thor Forums
