RV Tire Safety
with RV tire expert Roger Marble
Previously I posted the test results for my comparison of internal versus external sensor TPM systems. The weather was cool (“How accurate is your TPMS – Part two”) to cold (“More on internal vs. external TPMS temperature reporting”) back in March. Now I can report the results with the ambient temperature in the upper 80s.
All temperatures are in degrees Fahrenheit.
Internal System:
RF 102 LF 104 RRO 104 RRI 111 LRI 111 LRO 102
External System:
RF 73 LF 75 RRO 71 RRI 71 LRI 82 LRO 80
I was driving 65 mph with cruise on a level stretch of Interstate. The sun was fully on the left side of the RV.
Difference between Internal and External:
RF 29 LF 29 RRO 33 RRI 40 LRI 29 LRO 22
These results tend to match the previous runs with the internal reporting about 30 F hotter than the external sensors.
Again I do not consider the results of a comparison between the temperature readings to be “meaningful” in the sense that the internal sensor numbers are useless.
Suggestion: If you have an external sensor TPMS I would continue to use that system. Just be aware that the temperature readings are probably in the range of 27 to 40 F cooler than the temperature readings your friend would be getting with their internal sensor system. If you are concerned, you could change your High-Temperature warning level with your external sensor system from the factory 158° F to about 145° F. Just be aware that if in Phoenix or Death Valley or other location where the ambient temperature exceeds 120° F, you may get a high temp warning. If you do, just pay attention to the pressure readings to be sure you are not losing any air pressure.
Since tire temperature is also a function of load and speed, you might bump up the High-Pressure warning level 5° F until you are not getting a warning simply because it is hot outside. Of course, it might also help to slow down a bit as that will also result in lower tire temperature.
Bottom Line: There is a difference between temperature readings based on sensor location. BUT this does not automatically make one type of system better or worse than another. As I said in this post, I am not a fan of TPMS temperature readings no matter which type sensor you run.
Read more from Roger Marble on his blog at RVtiresafety.net.
##RVT855
