Community Forums

copter827 · 04-28-2021, 04:05 PM

Wondering if anyone else has experienced this. When I tow my 5er tandem axle RV with my F250 which has a single exhaust tail pipe on the r/s of the truck, here's what I'm seeing on my TPMS. L/F tire = 105*F. L/R tire = 110*F. R/F tire = 115*F and the R/R tire = 120*F. All tire pressures were confirmed to be the same before the trip began and were inflated to the max PSI rating for the tire. Here's my theory, what do you think? So, just like my Harley, the front cylinder runs cooler than the rear cylinder because it gets the air first and any heat blown off the front cylinder means hotter air for the rear cylinder. And, because the rear cylinder is tucked in behind the front one, it just doesn't get as much air to begin with, hence, it runs hotter. Same thing with the tires in my opinion. So why do the right set of tires run hotter than the left side? I believe that's due to the engine exhaust from the tail pipe blowing hot exhaust on the right side tires. Has anyone else experienced this? Anyone have dual exhaust that has relatively even temps on both sides? Might be a good reason to invest in a dual exhaust system.

R.Wold · 04-28-2021, 04:09 PM

I think it’s more likely that the right side is carrying a little more load than the left. Ever weight each side independently?

coachmanjay · 04-28-2021, 04:22 PM

What normally what happens is the sun side gets hotter along with the tire that has the exhaust exiting next to the tire

**Lt Dan** · 04-28-2021, 07:41 PM

First off, Welcome to IRV2!

My right front tire shows higher temperature 10-15 degrees hotter, the right rear a little lower but more than the left. Totally due to exhaust on the right side.

RVnAggie · 04-28-2021, 09:03 PM

Doubtful that it’s related to the exhaust. It’s a long way from the end of the tailpipe to your trailer tires, and at highway speeds the exhaust gas is dissipated pretty quickly I believe.

I experience the same thing with my TPMS. it’s most likely due to the crown in the roads; the trailer leans to the right which throws more weight on the right tires so they run a little hotter than the left.

Try this experiment.....When traveling, if you have an opportunity on a divided 4 lane to drive in the left lane (other side of the crown) for a few miles without making enemies in traffic, do it and see if right side cools down a bit and left side heats up. I did this simple test on two different occasions and that was the result both times. Enough proof to cause me to drive and not worry about it any more.

Safe travels,

Isaac-1 · 04-28-2021, 10:12 PM

I am dealing with something somewhat similar at the moment, though mine was a bit more extreme, and was caused by brakes slightly dragging

dskyward · 04-28-2021, 10:30 PM

You can test further and swap each side sensors to the opposite side to see if the trend is confirmed. I’ve not paid any attention to this scenario in my TireMinder TPMS, but we’re towing 352 miles tomorrow morning and will try to pay attention at the start temps, then later on various highways, and switching lanes.

copter827 · 04-29-2021, 10:11 AM

Thanks to everyone taking the time to read this and reply. I'm still not convinced that the exhaust doesn't have something to do with it but I'm not going to go through the expense of adding dual exhaust to my truck just to test that theory.

However, I didn't think about the road crown and the right side carrying more weight. I drive in the right lane 99% of the time so that could have something, if not everything, to do with it. I'll try the left lane next chance I get if I can stay over there without causing someone to have a melt down. I don't like left-lane cruisers so don't want to be one of those guys.

Jkwilson1989 · 04-29-2021, 11:12 AM

I doubt even a salamander heater would have any effect on the tire at that distance at highway speed.

rffowler55 · 04-29-2021, 11:13 AM

I agree that the weight distribution, slope of the road and other factors will impact the tire pressure and temperature fluctuations you are noticing more than the exhaust. I have rarely seen even 2 of my 6 tires reporting the same pressure or temperature even though all 6 tires start out at the same cold pressure setting. I always find it interesting to watch the TPMS readings because you can really see how much outside temperature, texture of the paving, grade and other factors impact your tires, it really makes you appreciate having a good tire that has capacity to absorb the variations in conditions.

dskyward · 04-30-2021, 07:14 PM

After yesterday’s tow out west to Ft Davis TX on I-10, my left side trailer tires were running 11 deg hotter at times than the right side. Exhaust pipe only on right rear on the Ram dually. The kitchen slide (w/res fridge/conv micro/stove oven/pantry etc) on the left side is much heavier than the dinette slide on the right. So more weight = hotter temps. It was a 55 deg air temp most of way thru the cold front with rain half the time.

bddadles · 05-01-2021, 07:29 AM

I agree with the others about the weight distribution and road surfaces and even the position of the sun. I definitely don't think your exhaust has anything to do with it.

cletesingler · 05-06-2021, 06:47 PM

I have been obsessive about tire pres and temp as I claim the record of blowing or failing every OEM Chinese tire on 4 new RVs - then bought and installed TM TPMS. I have the TM77 controller mounted in my face on the dash, so I watch the pres and temp of the tires more often than monitoring GPS. Yes there are variations we can't easily explain, but when I noticed one tire pres and temp climbing faster than the others on a hot TX day, I was not only alarmed, but had to actually stop and take pres out of the tire - then found a dragging brake and hot wheel......I reminded TM engineers that a lower than engineered high difference temp is maybe needed. I think that if the 4 tires temp and press differ by more than 5 degF, that is reason for attention; and yes it happens too often with TX black road temps over 125 degF. And, I can attest to the fact that the TM announces a blowout exactly 1 second before the tire starts shredding!

jacknife · 05-07-2021, 08:47 PM

The design engineers use computers and testing for tire heat parameters. The tire pressure is dependent on the weight the tire is carrying . The max tire pressure is not always the correct pressure to use . Especially if you are running G rated or higher . Those side walls are thick and filling them to 110 on a 14 k trailer is like riding on bricks . Tire heat will vary as to where the sun is ,the crown in the road , how much one side weighs more than the other ,temp of the road surface and speed . Good rubber = peace of mind .