Towing on Extremely Hot Days

[PIC]

Hey All, Looking for some practical or cautionary advice on long days towing in extreme heat; 90 degrees or higher, even in the 105+ range. There are some 7-8 hr days planned through the Southwest. I am concerned about the strain on the truck (2014 Toyota Tundra 5.7 2 wheel drive) and on the trailer's 14" tires (2018 Micro Minnie 2106 FBS). My speed limit will be 65 MPH and the tires will be filled to their recommended limit. Am I asking too much of our equipment? PAT

[Tucsontoy]

I live in the SW heat and pull often in 105 and up. Flat ground, you will be fine. It is the hills that get you. Watch the engine and tranny temps close. If close to the red zone just pull over and let the truck rest. Once in a while that will work. If you want to do it a lot the extra cooling for the engine and transmission will be recommended. Heat will find the week links. Your tires are almost new so if there are not curb damages and not overloaded you will be fine. If you have to stop, have enough beer. Safey travels. Enjoy.

[PIC]

Ahhhh, Beer is the answer. Coming out of FL heading to NM,AZ,NV, then into cooler Sierra Nevada from there into the Northwest and on back. Was just getting concerned about the heat. AT least it will be dry heat which coming from FL will feel better than 90s here and equal humidity

[bigb]

If you do have to pull over to cool down DO NOT shut the engine down. Shutting down an overheated engine and automatic transmission is a sure way to cook the fluid and clutches even worse. Can you say "Heat Soak"? Idling at a slightly elevated RPM with the heater on full will cool you down pretty fast as well.

Driving the hills you can shut off the AC while climbing the really steep ones, the downhill side will cool you down quick. Another thing about the AC, running it on "MAX" or recirc will reduce the condenser temps which in turn means cooler air to the radiator.

[PIC]

Great tips bigb. Thanks Pat

[VI Roamers]

Remember your engine produces heat, but your heater in the cab sends off engine heat. I climbed out of Palm Desert to the mountains heavily loaded when the temp at the bottom was 117F. Heater and fan on full blast, windows open, low speed because the engine only needs to produce lower horsepower so less heat at the lower speed. Lingered near the red line, but steadily climbed with no complaints.

[Ray,IN]

Back when I owned a 1976 MH on a Dodge truck chassis, the coolant temperature rose past the red line climbing a mountain. I stopped at the top in the trucker pull-out to allow the coolant to cool to normal limits, when a trucker came to me and said if i would slowly pour a glass of water over the radiator it would help, it DID! The temp gauge fell back to normal limits within a few minutes and I was back on the road again.
Had that been an newer aluminum engine_____ can you say toast?

[jerichorick]

Check your tire rating. Yes, they may be new but trailers have a high tire failure because the manufactures use the lowest grade they can get away with. Having too robust a tire is better than a blowout in 105* heat.

[ke4jr]

Last week while going to Yosemite National Park, my GPS took me through some winding hills and for the first time ever the temperature gauge on my Cummings 300 came to the RED line. I stopped, kept it running and it quickly cooled down and we made it to the campground. There, we checked and all the fluids and all were fine so in the morning we continued out trip.

Afterwards returning home to Florida from California I encountered the same overheating issue on those long hill climbs, never made it to the RED line, but close. Mind you in Arizona, it got to 111 degrees.
Before we pulled into the next campground, I Googled for a Cumming mobile repair near me and he advised me after we parked and the engine cooled about an hour to spray a de-greaser all over into the radiator grill and with a hi pressure water spout on a hose, to spray pressurized water to clean the entire radiator... I was amazed and surprised all the dirt, mud and black crap that was washing down the other side on to the ground. I was parked on a grass camp site.
Surprisingly logical we drive through some unpaved dirt and gravel roads that produce clouds of dust, all being pushed into the radiator by the fan.
After the wash, turned on the engine, accelerated to 1500 rpm's a couple of times and I could see all the crap being blown out through my rear view camera.
Perfect suggestion from the guy, from that point on the gauge never made it pass the 3/4 mark when climbing hills.

[Walt523]

Never fill your tires to the limit. Fill your tires based on load. On very hot days your tire pressure will go up dramatically , increasing the chance of a blow out, plus there is no to give you an unneeded harsh ride. For example on really hot days my tire pressure will increase about 25 psi. Now my limit on my tires is 110 psi and it’s a harsh ride. Michelin states for my load I can inflate to 85-90 psi and on really hot days it still rises to over 105 psi, but not pushing the tire on psi. Many people inflate there tires to the max and that’s just not how tires are supposed to be inflated.

[LarryW]

“Never fill your tires to the limit”

Sorry, Walt, but I follow manufacturer recommendations on TT tire pressure. Have a blow out, admit your tires were not inflated when cold to max pressure and you’re out of luck with any tire warranty or liability. Underinflation also lowers the tire max weight rating.

Additionally, under inflation causes additional heat due to flex in the sidewall. Please remember OP is pulling a TT not driving a MH.

[LarryW]

Please note these two opinions on speed and underinlation.

From etrailer at
https://www.etrailer.com/question-234245.html

“You want trailer tires to be inflated to their maximum psi when they're cold. Some people feel the need to under inflate their tires when driving through excessive heat when can often backfire on them. Under inflation is one of the main reasons for tire failure.”

And from Tire Rack at

https://www.tirerack.com/tires/tiret...jsp?techid=309

“Special Trailer (ST) Tire Maintenance
Allowing inflation pressure to drop can dangerously overload a trailer tire, resulting in excessive heat buildup and possibly a blowout. And while not always resulting in immediate tire failure, even a short period of operating a significantly under-inflated trailer tire can cause hidden internal structural damage that can result in tire failure. Tire load capacity is reduced while tread/sidewall deflection and heat buildup are increased anytime a tire is operated without enough inflation pressure to carry its load. The chance of failure greatly increases if trailer tires are underinflated or overloaded.”

[PIC]

Good advice on the cooling system. Not gonna take it for granted that all is okay. I will have it checked and maintained before we go. PAT

[PIC]

Thanks for all of the tire info. I will check them cold and max the psi. I will trailer at no more that 65 mph and take plenty of breaks in the extreme hot zones. When it comes time to replace them I will get the best tires available. One reason we purchased the Micro Minnie was the axles. 2 of them and each are 3,500 lb weight rated vs. most others that are only 2,500. We won't ever get close to that weight but then again we won't have to worry about being overweight either. 2 things I have learned so far; slow down on the highway & be gentle with everything onboard they are not built like they are for a house. THANKS for all of the feedback PAT

[jerichorick]

Good thread guys!

The radiator cleaning is also great advise for the tow vehicle. Even the towed vehicle for us with a car on the tail.

As stated about the tires. No tire manufacturer will advise not to fill to max psi cold. On passenger vehicles this can be a problem for ride comfort and tire ware. All tires are engineered to deal with rolling psi buildup. What I think is a poor option is running tires at max load weight, as was the case with the original tires on my coach. I don't see overkill on load size as a problem with tires for safety reasons. I had a blowout on my last coach, Lots of damage from the tire. Got off the road safely.

[LarryW]

PIC, 65 mph is the MAX rated speed on many TT tires. Some newer, more expensive TT tires are now rated at 81. Any item pushed at max in the RV world concerns me.

[Ray,IN]

Originally Posted by LarryW

Please note these two opinions on speed and underinlation.

From etrailer at
https://www.etrailer.com/question-234245.html

“You want trailer tires to be inflated to their maximum psi when they're cold. Some people feel the need to under inflate their tires when driving through excessive heat when can often backfire on them. Under inflation is one of the main reasons for tire failure.”

And from Tire Rack at

https://www.tirerack.com/tires/tiret...jsp?techid=309

“Special Trailer (ST) Tire Maintenance
Allowing inflation pressure to drop can dangerously overload a trailer tire, resulting in excessive heat buildup and possibly a blowout. And while not always resulting in immediate tire failure, even a short period of operating a significantly under-inflated trailer tire can cause hidden internal structural damage that can result in tire failure. Tire load capacity is reduced while tread/sidewall deflection and heat buildup are increased anytime a tire is operated without enough inflation pressure to carry its load. The chance of failure greatly increases if trailer tires are underinflated or overloaded.”

To add to your excellent post, the RMA Rubber Manufacturers Association says the vast majority of tire failures(over 80%) are the result of under-inflation/overloading.


FWIW, no tire manufacturer will recommend running less air pressure than that stated on the Federal Tire Placard that's required to be in every on-road vehicle.

[Walt523]

Originally Posted by LarryW

“Never fill your tires to the limit”

Sorry, Walt, but I follow manufacturer recommendations on TT tire pressure. Have a blow out, admit your tires were not inflated when cold to max pressure and you’re out of luck with any tire warranty or liability. Underinflation also lowers the tire max weight rating.

Additionally, under inflation causes additional heat due to flex in the sidewall. Please remember OP is pulling a TT not driving a MH.

That’s if that’s what the manufacturer says to do, but many don’t recommend that. For example my 5th tires were not recomended to be max inflated, it was load based. My motorhome tires are load based. Further more the first thing you should do if taking OEM TIRES into hard conditions is replace them with a better tire or LT TIRE. The term China bomb tires is well earned. The vast majority of people don’t even know what the manufacturers recomended tire inflation is, some Chinese tires information is nearly non existent. One of my current St trailer tires just gives a psi NEVER TO EXCEED.

[Walt523]

Originally Posted by Ray,IN

:

FWIW, no tire manufacturer will recommend running less air pressure than that stated on the Federal Tire Placard that's required to be in every on-road vehicle.

Michelin has charts on there recomended tire psi based on load. As does continental and others.

A tire is not under inflated if you following the recomended psi for the load on the tires.

If you increase the load and not the psi then you under inflated. Have you guys never been to a rallies tire seminar with the tire reps explaining tires?
Every camper I’ve ever owned has been weighed and balanced.
How many have even weighed their campers? Many are over loaded for tires , side to side load and axles.

[LarryW]

Walt, we are speaking of TT and 5er tires. MHs are different. Please don’t confuse newbies with TT/5er pressures vs. MH pressures. Maximum load capacity on a TT tire is only achieved at the maximum cold pressure listed on the tire itself. Again, MHs are different.