tire temperatures - why variation?

[CHICKDOE]

I have read many, many posts about tires, tire failures, tire pressure, etc. and I do not want to have a problem. so I am trying to be diligent. I have a 2015 forest river cardinal 3825fl 5th wheel that weighs 16,000 lbs. it came with 4 goodyear G614 RST tires size LT235/85R16. these are load range G tires with max psi of 110. from the tire inflation charts it looks like I should inflate the tires to 95 PSI, which I did. yesterday we drove about 300 miles going north so the sun was on the drivers side tires all afternoon. I have a tire tracker 400 TPMS installed on the tires. I took many looks at the TPMS during the drive and noted variation primarily in the temperature being reported for the tires. here is a typical reading from the TPMS.

left front 100 psi, 116 degrees
right front 102 psi, 104 degrees
left rear 101 psi, 120 degrees
right rear 99.5 psi, 105 degrees

as you can see the pressure on all tires is pretty consistent. but the temperature seems to vary more, and it is interesting that the drivers side is hotter than the passenger side. remember, the sun was shining on the drivers side.

so here are the questions:

1. what temperature should be considered normal and what is high (I looked at the tire tracker manual and it sends a high temperature alert at 175 degrees)?
2. why the variation between drivers side and passengers side, especially when the pressure does not seem to vary. could this be the result of the sun on the drivers side tires?

any insight you can offer would be appreciated. during our drive we saw a couple of rv's on the side of the road with blown tires and I DO NOT WANT THIS EXPERIENCE!

[VinceU]

More weight (equipment/gear on left side? A scale would would confirm. Your Temps are close however.

[Happy Vibe]

The sun will definitely heat up the tires on the side facing it. I have seen a few psi difference between the sunny side tire to the shade tire when the trailer is just sitting in my driveway.
Remember those charts show the maximum weight the tire can hold at a given psi, do you really want to run the tire at it's maximum or put a few more psi in it to give you some margin.

[Paul M]

The way I understand it there can be many factors. Sun, Load, Brakes, Wheel bearings. Sun and load have been mentioned, so that leaves brakes and bearings. If a brake is not releasing far enough, or a bearing is a little tighter than another, this can effect temps.

[f5moab]

On my last trip through the Arco desert, my right side tire ran exactly 9 degree hotter than the left. Right side was facing the sun. After entering the canyons and losing direct sunlight onto the tire, within (I'm guessing) 20 miles, the tires were almost identical in temps.

[CHICKDOE]

to f5moab, thanks. seems as if you may have noticed the same pattern. when we leave our current site and drive to the next I am going to continue to monitor the temperature on the sun versus shade side to see if the pattern reoccurs. but it seems entirely possible that direct sunlight on one side could cause the baseline temperature of those tires to be hotter than the ones in the shade on the other side. I would think this differential would remain the same even when traveling. the friction caused heat should be the same on both sides and just add to the sun induced differential. I good test might be to take the temperature at rest with one side facing the sun and the other in the shade. i'll try to do this also.

[OldCoot]

My tires have about a 5°-10° difference just sitting in front of my garage from sunrise until the sun gets over to the west side. The side the sun shines on is always higher by 5°-10°. The shade side is always within 1°-2° of the ambient temp.

[Jim34RL]

Originally Posted by CHICKDOE

I have read many, many posts about tires, tire failures, tire pressure, etc. and I do not want to have a problem. so I am trying to be diligent. I have a 2015 forest river cardinal 3825fl 5th wheel that weighs 16,000 lbs. it came with 4 goodyear G614 RST tires size LT235/85R16. these are load range G tires with max psi of 110. from the tire inflation charts it looks like I should inflate the tires to 95 PSI, which I did. yesterday we drove about 300 miles going north so the sun was on the drivers side tires all afternoon. I have a tire tracker 400 TPMS installed on the tires. I took many looks at the TPMS during the drive and noted variation primarily in the temperature being reported for the tires. here is a typical reading from the TPMS.

left front 100 psi, 116 degrees
right front 102 psi, 104 degrees
left rear 101 psi, 120 degrees
right rear 99.5 psi, 105 degrees

as you can see the pressure on all tires is pretty consistent. but the temperature seems to vary more, and it is interesting that the drivers side is hotter than the passenger side. remember, the sun was shining on the drivers side.

so here are the questions:

1. what temperature should be considered normal and what is high (I looked at the tire tracker manual and it sends a high temperature alert at 175 degrees)?
2. why the variation between drivers side and passengers side, especially when the pressure does not seem to vary. could this be the result of the sun on the drivers side tires?

any insight you can offer would be appreciated. during our drive we saw a couple of rv's on the side of the road with blown tires and I DO NOT WANT THIS EXPERIENCE!

How did you determine the tire air pressure to use based on what weight?

Have you individual weighed each tire load as you would travel in the trailer?

I have a Cedar Creek 34RL which has a gross weight 16,000 + LBS; but I have weighed my truck and trailer combination and the rear axles loads were in the 10,200 LB range. But I do not know the individual loads on each wheel.

I also have G rated tires on my trailer but they are an ST tires instead of the LT tires that you have. But I also use the maximum air pressure on my trailer tires 110 PSI. I have always been told to run the maximum air pressure in trailer tires to prevent overheating and failure due to under-inflation.

I use an IR heat gun to measure my tire temps and look for a spread between the two tires on the same side. If one is considerably higher than the other I would check this out but with only 3 to 5 degree difference I do not worry. Brakes and wheel bearings are also checked with the heat gun on the trailer. The rear differential on the TV and its rear tires at the same time.

Even my old camper which had Michelin XPS Ribs on it were run at maximum air pressure 80 psi. These tires were on the camper for over 4 years with no issues; no failures at the maximum tire air pressure.

[rwmurphy]

I have the tire tracker system also with some strange temps
Left Rear 62 degrees. 81.8 psi
Right rear 91 degrees. 84.7 psi
Left front. 100 degrees 82.6 psi
Right Front. 105 degrees. 84.4 psi

The 62 degrees seems a little strange

[CHICKDOE]

to jim34rl and all the others: greatly appreciate your insight! thank you! there has been a theme from this post and others that say just inflate the tires to the max psi stamped on the tire. my question is if this were recommendation then why worry about the tire inflation charts that vary inflation pressure to load? I have read that over inflating tires causes premature wear but it is not as serious as underinflation. yet many people appear to be inflating to max psi and just going with it. sure would like to get any many thoughts on this as I can? again, I want to avoid problems. we are on an extended trip and will be towing a few thousand miles over the next few months. are there any ex-tire company experts out there to respond?

[wamafi43]

Most of the info is about trailer tires, I always run mine what the trailer manufactores recommend, written on the side of the trailer.
Here comes my question: what about the tow vehicle. I have a fifth wheel dry weight 14000 pounds and a GMC 3500 dual wheels. What should the tire pressure be on the rear dual wheels. So far I have them pumped up to max as written on the side wall.
Is this correct, or I'm over inflated since they are dual wheels?
Anybody know's please let me know!

[Harkerr]

I see 10 degrees sun to shade on my rig. Inflating to max number on sidewall will reduce flex and temperature. This is a cold and shaded number.

[OldCoot]

CHICKDOE , inflate your trailer tires to the max cold pressure on the side of the tires and you will be just fine. The trailer tires are usually so close to the max load that it is not worth the effort to try to match the pressure to the load. The trailer manufacturers struggle with knowing how to assemble a trailer and the d--- sure don't know anything about tires. JMO

[CHICKDOE]

here's what's bugging me. the tire inflation sticker on the trailer says inflate to 80 psi with no mention of altering this due to loaded weight. but this sticker also says it is for a completely different tire than what is on the trailer. (how can they do this)? asked the dealer and the tech says 85 psi of the top of his head. no reference to anything. contacted goodyear and they refer you to their tire inflation table. went to local goodyear dealer and he says 90 psi (again off the top of his head). many on this forum say max psi on stamped on the tire. all of these should be reliable sources. can you see the dilemma?

[mcnabbwr]

Unless you can verify the tire sticker on the unit with the actual tire don't believe it. My units sticker stated 16 inch G rated tires with a max psi of 110. It came equipped with better tires rated at H load 17.5 inch at 125 psi. Moral to the story is look on tire and inflate to maximum cold psi and no worries.

[wamafi43]

Wow, that is a lot of pressure, have had a blow out on a tire with max. 80 psi , I could just imagine what damage a 125 psi tire could do.
You are right, the pressure reading on the side wall is the number the tire should be inflated too (cold tire reading)

[Jim34RL]

Originally Posted by CHICKDOE

to jim34rl and all the others: greatly appreciate your insight! thank you! there has been a theme from this post and others that say just inflate the tires to the max psi stamped on the tire. my question is if this were recommendation then why worry about the tire inflation charts that vary inflation pressure to load? I have read that over inflating tires causes premature wear but it is not as serious as underinflation. yet many people appear to be inflating to max psi and just going with it. sure would like to get any many thoughts on this as I can? again, I want to avoid problems. we are on an extended trip and will be towing a few thousand miles over the next few months. are there any ex-tire company experts out there to respond?

Ok! I see other have respond to you also telling you to inflate to the maximum air pressure on the side wall of the tire. I agree!

Now I do use air inflation tables on my truck tires but I am running non-stock size tires on my truck LT285/70R/17 126R Nitto Dura Grappler tires. I also know the actual axle weight loaded and unloaded; so I know what air pressure to use.

I do know of others who use the tire air inflation chart for trailer tires but they also know the individual wheel weights of their trailer. They have actually weighed each axle and than each individual tire to get the proper loads so they can use the inflation tables. Have you done this weighed each individual tire to see what the weight that tire is supporting? If not air the tires to the maximum air inflation listed on the side wall of that tire and be safe.

I bet you will even see a cooler running tire air temperature on your TPMS system. Under inflated tires will run hotter than properly inflated tires.

[CHICKDOE]

thanks to all.


I am going to inflate to max psi stamped on the tire which is 110 psi for goodyear G614 RST size LT235/85R16 load range G. we are towing tomorrow and I will be monitoring them.


as far as the sticker on the trailer goes I am ignoring it. it is for a completely different tire. how can forest river put a sticker on the trailer that does not match the actual tires installed. seems like somebody else mentioned that also. seems that this ought to be violating a safety law or two. they go overboard about not overloading GVW but then give improper tire info.


finally, so much for the dealer and the local goodyear dealer. they were just winging it. neither asked for the type of tire, the trailer weight, or anything. they just new it was 80 lbs in one case and 90 lbs in another. who do you trust?

[Tireguy397]

Ok after 34 years in the tire business I feel qualified to put in my 2 cents. More than half of my years were spent dealing with commercial trucks and rv's. If you ask 3 different experienced tire people about loads and air pressures you will probably get 3 different answers. Tire manufacturers say that air pressure should be based on load. This means that if you are taking the tt to the lake this weekend with a full load and water in the fresh tank, you should weigh the trailer and adjust tire pressures for that load. Now when you come home and the fresh water tank is empty and you have eaten all the food and drank all the beer, you need to weigh the trailer again and readjust the pressures. I take great care of my tires and I wouldn't go through that. Just inflate your tires to max sidewall pressure and forget it. Max pressure gets you 2 things. Best load carrying capacity and best fuel economy. The more air in a tire, the easier it rolls. The worst that could happen is that it wears prematurely in the center. So it's a trade off, tires wore out a little sooner but you saved hundreds in gas. Check pressures when tires are cold. Cold tires have been sitting for at least 8 hours and not driven more than a mile to get to the gas station. Tires should be checked before EVERY trip and never bleed air from a hot tire. Depending on load and ambient temperature, tires can gain many pounds of pressure when they are hot. If you let air out when they are hot you will be underinflated when they are cold. You can't pop tires like a ballon by blowing a little to much air in them. Tire can take several hundred pounds of pressure before they explode. Most tire issues happen due to underinflation and because someone didn't take care of theirs. I hope this helps.

[jk510]

I used to have a TPMS system similar to your tire tracker and I always wondered just how accurate the temps were. With the sensor sitting out there on the valve stem it always seemed the the sun shining on the black sensor would heat it up more than the air in the tire.