Oil Temp while Towing

[shmit140]

Somethings up if you’re running that high with 5k. Could there have been a bad head wind? If the truck checks out fine I’d check to make sure your trailer wheels are free spinning. I’ve been worried about my temps in AZ 100+ heat up grades. I peaked 264 oil and 237 coolant on my last run and I’m looking into ways to cool it down a little. I have the eco D though. Towing 7600-7700#. Hope you get her checked out and figure a way to keep those temps down. I ran cooler on this hotter run by keeping speeds down.

It was a bit windy but I don’t remember if it was a head wind. It is always windy here so I don’t pay too much attention. My truck is just a hot running truck. Maybe the sensor is slightly off and high. We went to the mountains for the day yesterday so no trailer or anything. It was around 94 degrees when we left outside. There is a long hill climb and with the A/C on and empty it was still running 212 coolant, 177 transmission and hit 238 oil temp up that hill. And I have full synthetic in it now (that oil filter is in an awful spot btw!). Just normal cruising empty with temps above 90 outside my oil runs at 222F pretty much all the time with the A/C on. Coolant varies between 203 and 210ish. On the way home it was really late and only 72 outside. The truck ran 230F oil temp up the back side of that hill. And this was just at a speed limit of 60 mph. I’m a bit worried about our trip coming up. We have to leave at the hottest part of the day. It will be 108 degrees out when we head up for the 4th. I might have to take it slow with the trailer. At least I know the oil in it now can handle over 300F without breaking down.

 

[834k3r]

I look forward to the results! I have a trip coming up on the 4th of July and it is supposed to be really hot as well. I'm going to change my oil and put in Pennzoil Ultra Platinum for some peace of mind at least. Can you also post your transmission gear, rpm, and speed when you do climb a hill too. As close of numbers as you can report at least. I asked the dealer to look up max temps for me that are allowed and they came back and said they couldn't find anything listed from FCA. Nothing on the coolant, transmission or oil. Very frustrating that they don't know. My brother in law has a very similar truck to me but a 4th gen and tows a travel trailer larger than mine and he hasn't noticed too high of oil temps but his transmission get to 240. Mine barely cracks 200 on long hills. Very interesting that the 4th gens run different.

Trip done. Temperatures yesterday afternoon in the valley were 110* or more, temperature at the top of the climb was 107*
Though I cropped it out, the cruise was on 65 MPH the whole drive up the hill, 4500 rpm on the tach until it started leveling out at the top. Once at the top, the hills of the Palouse still roll a bit, but the engine cooled fairly quickly (in about 10 minutes of driving at 65, oil temp dropped to about 230*).

edit: I'm not sure why the gearing shows the way it does. Tow/Haul mode was on, gear override was off.
2nd edit: Oil Life-O-Meter at the beginning of the trip showed about 27%; ~24% after the trip.

Pictures:
Idle at beginning of trip: idle after about 1/2 mile drive away from my house
Level travel at beginning of trip: level travel about 20 miles away from my house
Beginning of hill climb: starting the climb up the Lewiston hill
End of 7% grade: peak of engine work; where road transitions from 7% grade to ~5%.
Near top of hill: self-explanatory.

I think there's a strong correlation between engine temps and ambient air temperature (as should be expected).

 

[shmit140]

Trip done. Temperatures yesterday afternoon in the valley were 110* or more, temperature at the top of the climb was 107*
Though I cropped it out, the cruise was on 65 MPH the whole drive up the hill, 4500 rpm on the tach until it started leveling out at the top. Once at the top, the hills of the Palouse still roll a bit, but the engine cooled fairly quickly (in about 10 minutes of driving at 65, oil temp dropped to about 230*).

edit: I'm not sure why the gearing shows the way it does. Tow/Haul mode was on, gear override was off.
2nd edit: Oil Life-O-Meter at the beginning of the trip showed about 27%; ~24% after the trip.

Pictures:
Idle at beginning of trip: idle after about 1/2 mile drive away from my house
Level travel at beginning of trip: level travel about 20 miles away from my house
Beginning of hill climb: starting the climb up the Lewiston hill
End of 7% grade: peak of engine work; where road transitions from 7% grade to ~5%.
Near top of hill: self-explanatory.

I think there's a strong correlation between engine temps and ambient air temperature (as should be expected).

This is info is so awesome and exactly what I needed to see! Thank you so much! That is exactly how my truck acts although I was towing 5500Lbs. I’m glad to see I’m not the only one with higher temps. I’m definitely sticking with full synthetic that I know can handle these almost 300 degree oil temps.

So I’m guessing you didn’t have any issues? No warning lights, engine power reduced warnings like the ecoboost’s do? Seems like Ram thinks these temps are acceptable by the looks of it. BTW I also noticed oil life dropping pretty quick during my towing trip compared to regular driving.
I like that the transmission doesn’t get as hot compared to the 4th gen’s. Oil is easy to change. I’d rather the oil get hot over transmission fluid if I had to choose. Tranny fluid changes can get expensive and time consuming. 203 briefly isn’t that bad really for that hot of a day after that climb for a transmission.
Thanks again for this test. I’m sure it will help out many people. Now I know what to expect if I head your way someday (we are in the Boise area).

*Edit 1 - Were you running your A/C like normal going up that hill? At those outside temps I’m guessing you had the A/C going pretty good?

 

[834k3r]

This is info is so awesome and exactly what I needed to see! Thank you so much! That is exactly how my truck acts although I was towing 5500Lbs. I’m glad to see I’m not the only one with higher temps. I’m definitely sticking with full synthetic that I know can handle these almost 300 degree oil temps.

So I’m guessing you didn’t have any issues? No warning lights, engine power reduced warnings like the ecoboost’s do? Seems like Ram thinks these temps are acceptable by the looks of it. BTW I also noticed oil life dropping pretty quick during my towing trip compared to regular driving.
I like that the transmission doesn’t get as hot compared to the 4th gen’s. Oil is easy to change. I’d rather the oil get hot over transmission fluid if I had to choose. Tranny fluid changes can get expensive and time consuming. 203 briefly isn’t that bad really for that hot of a day after that climb for a transmission.
Thanks again for this test. I’m sure it will help out many people. Now I know what to expect if I head your way someday (we are in the Boise area).

*Edit 1 - Were you running your A/C like normal going up that hill? At those outside temps I’m guessing you had the A/C going pretty good?

Those are good questions. From my perspective in the cab there were zero issues from the truck. No warning lights, no chimes, no loss of power. It was actually pretty impressive to me (this Ram is my first full-size truck; previous towing rig was a Honda Ridgeline).

We did have the air conditioning on Auto the whole way up, and the system didn't cut off at all. I'm curious to know if the eTorque system helped the a/c stay on even as the engine was running hot and hard.

Couple of points for future investigation:
- Does low oil life contribute to higher oil temperature?
- What would the engine temps look like if the outside temperature was in the 60s or 70s?

If my son has a baseball tournament down there next spring, I should be able to test both of these points and post the results here.

 

[shmit140]

Those are good questions. From my perspective in the cab there were zero issues from the truck. No warning lights, no chimes, no loss of power. It was actually pretty impressive to me (this Ram is my first full-size truck; previous towing rig was a Honda Ridgeline).

We did have the air conditioning on Auto the whole way up, and the system didn't cut off at all. I'm curious to know if the eTorque system helped the a/c stay on even as the engine was running hot and hard.

Couple of points for future investigation:
- Does low oil life contribute to higher oil temperature?
- What would the engine temps look like if the outside temperature was in the 60s or 70s?

If my son has a baseball tournament down there next spring, I should be able to test both of these points and post the results here.

Just a quick update. We made it up to McCall, ID and my truck did a little better. I dare say the full synthetic oil is helping…but can’t prove it. We were towing the same trailer and exact same setup and cargo. It was even hotter today than last time, between 105-107F outside. My truck stayed under 248F oil temps most of the way at 65mph. Last trip at 65mph it was nearly always in upper 250-low 260’s. Highest I hit with full A/C going at 65mph was a long climb:

235F coolant, 199F trans, 275F oil temp.
This was running 4th gear, 65mph, 4.5K rpm.

It seemed to have 10-15F cooler oil temps this trip with hotter weather and nothing different except my oil change. This was running 4th gear, 65mph, 4.5K rpm.

 

[silver billet]

I would definitely be running a good 5w-30 with those temps. Redline is a great candidate (I stayed at 230 on a 3 hour pull just recently, but outside air was a nice 80 to 85 degrees outside so...), at 63 mph, 2300 rpms. Some guys are even running 5w-40 or 0w-40, but all that voids your warranty of course. This trip I didn't have much in the way of hills, just a 30 second climb which raised the temp maybe 2 degrees.

 

[834k3r]

Just a quick update. We made it up to McCall, ID and my truck did a little better. I dare say the full synthetic oil is helping…but can’t prove it. We were towing the same trailer and exact same setup and cargo. It was even hotter today than last time, between 105-107F outside. My truck stayed under 248F oil temps most of the way at 65mph. Last trip at 65mph it was nearly always in upper 250-low 260’s. Highest I hit with full A/C going at 65mph was a long climb:

235F coolant, 199F trans, 275F oil temp.
This was running 4th gear, 65mph, 4.5K rpm.

It seemed to have 10-15F cooler oil temps this trip with hotter weather and nothing different except my oil change. This was running 4th gear, 65mph, 4.5K rpm.

So oil life could be a factor. Not surprising per se, but interesting to see in "real life" nevertheless.

 

[IvoryHemi]

Remembered to take a picture for you. These are my normal temps for towing 7,000 lbs

 

[silver billet]

Remembered to take a picture for you. These are my normal temps for towing 7,000 lbs

Those are my exact temps/psi as well.

 

[shmit140]

I would definitely be running a good 5w-30 with those temps. Redline is a great candidate (I stayed at 230 on a 3 hour pull just recently, but outside air was a nice 80 to 85 degrees outside so...), at 63 mph, 2300 rpms. Some guys are even running 5w-40 or 0w-40, but all that voids your warranty of course. This trip I didn't have much in the way of hills, just a 30 second climb which raised the temp maybe 2 degrees.

Do you run redline 5w-30 in your truck? I’ve considered a thicker oil but everyone says not to with the MDS system. I’m curious if others have been doing it long term with no ill effects to the lifters, cams, etc. But what I don’t understand is the 6.4L Hemi in the HD trucks are supposed to use 0W-40 full synthetic. It’s right in the manual on the new ones at least. Those trucks have MDS and I thought they were a very similar design otherwise so can the 5.7L Hemi take 0W-40 just fine? Other than it will void my warranty. Makes me wonder if FCA knew those HD 6.4L would run high oil temps in heavy towing and need a heavier oil.

 

[shmit140]

Remembered to take a picture for you. These are my normal temps for towing 7,000 lbs

View attachment 98651

Thank you so much! I appreciate all of your guys time posting your results while towing.

 

[silver billet]

Do you run redline 5w-30 in your truck? I’ve considered a thicker oil but everyone says not to with the MDS system. I’m curious if others have been doing it long term with no ill effects to the lifters, cams, etc. But what I don’t understand is the 6.4L Hemi in the HD trucks are supposed to use 0W-40 full synthetic. It’s right in the manual on the new ones at least. Those trucks have MDS and I thought they were a very similar design otherwise so can the 5.7L Hemi take 0W-40 just fine? Other than it will void my warranty. Makes me wonder if FCA knew those HD 6.4L would run high oil temps in heavy towing and need a heavier oil.

Yes I run RL 5W-30. MDS still engages for me when I forget to turn it off. But I always turn it off every time, so I can't say for certain whether it's worse than 5w-20, just that it still works.

There is at least one guy on a different forum that is running 0w-40 (full synthetic but not redline). Claims it works great, but again YMMV.

That is the theory yes; the thinner oil is speced for the hemi for tiny bit better MPG but (again theory) the 5w-30 or 0w-40 is actually better for the engine. Nobody really knows. If you start messing with the oil, I would highly recommend doing used oil analysis; basically you send your oil away to a lab like blackstone and they send you back a report telling you the amount of wear metals in the oil, how much life you have left in it, the viscosity etc. Actually the UOA's are a great idea even on factory oil.

 

[834k3r]

Do you run redline 5w-30 in your truck? I’ve considered a thicker oil but everyone says not to with the MDS system. I’m curious if others have been doing it long term with no ill effects to the lifters, cams, etc. But what I don’t understand is the 6.4L Hemi in the HD trucks are supposed to use 0W-40 full synthetic. It’s right in the manual on the new ones at least. Those trucks have MDS and I thought they were a very similar design otherwise so can the 5.7L Hemi take 0W-40 just fine? Other than it will void my warranty. Makes me wonder if FCA knew those HD 6.4L would run high oil temps in heavy towing and need a heavier oil.

The manual for my '21 says to use and API-certified 5W-20, but leaves the rest up to the owner:

Synthetic Engine Oils​

You may use synthetic engine oils provided the recommended oil quality requirements are met, and the recommended maintenance intervals for oil and filter changes are followed. Synthetic engine oils which do not have both the engine oil certification mark and the correct SAE viscosity grade number should not be used.​

​

Materials Added To Engine Oil​

The manufacturer strongly recommends against the addition of any additives (other than leak detection dyes) to the engine oil. Engine oil is an engineered product and its performance may be impaired by supplemental additives.​

 

[834k3r]

Update: Last weekend did the same trip, same trailer with cooler outside temperature (it was starting to snow as we headed up the hill). As you can see the ambient air temperature makes a big difference.

Interesting to see the coolant 5 degrees cooler than lower on the hill. I attribute that to the fact is was snowing hard at the top, and I waited until the road was mostly flat to take the picture.

 

[My1stHemi]

This was from a trip a few years back. Three mile “hill” towing 9000# 32’ TT. I used 5w20 Shell Rotella gas truck oil until it disappeared off the shelves.
You can see the temps at the start of the climb and at the end.
3.92’s with ORG, 6’4 box.

 

[SD Rebel]

Loved Shell Rotella Gas Truck, but the prices have nearly doubled for those who still have some in stock. Switched over to Pennzoil Ultra Platinum, it's still $25 at Walmart or Amazon for a gallon jug.

 

[should_have]

My oil temperature typical runs 20' hotter than my radiator. My concern is why does my transmission run hotter than most here posted on this thread.

 

[Dewey]

My concern is why does my transmission run hotter than most here posted on this thread.

I was always taught anything over 200 will kill the transmission on older vehicles. Maybe that doesn’t apply to these newer 8 speeds and tighter tolerances. They do seem to run hotter. My new 5th gen is even 15-20 degrees warmer than my old 4th gen. Seems about 185 degrees is the norm now and 195-200 when towing a 2500 lb load. That shows about mid range for the gauge so must not be concerning. Maybe it’ll drop a bit when broken in some but looks like yours is well worn in by now. Curious to hear what others run at.

 

[SD Rebel]

My oil temperature typical runs 20' hotter than my radiator. My concern is why does my transmission run hotter than most here posted on this thread.

Your parameters look normal to me.

Your coolant temps should be 200F - 220F regular cycle. At long idle in the heat, it will go up naturally to 230F. At that point, the fan will turn on at 230F and bring it down to 220F. However, under heavy towing, it can reach up to 240F even with the fan running. Overtemp warning is around 245-250F.

Your engine oil temp should mirror your coolant temp when cruising, but any type of idling or constant load will bring it to 10-20F higher than coolant. If heaving towing, the oil temp can go way beyond coolant temp, up to 285F under heavy load. The overtemp warning should be around 290F.

As for your transmission, you should be at around 185 after 10-15 miles of driving, up to say 195F-201F. I should never go much higher than that even when towing.

 

[should_have]

Your parameters look normal to me.

Thanks for the reply

Your coolant temps should be 200F - 220F regular cycle. At long idle in the heat, it will go up naturally to 230F. At that point, the fan will turn on at 230F and bring it down to 220F. However, under heavy towing, it can reach up to 240F even with the fan running. Overtemp warning is around 245-250F.

Your engine oil temp should mirror your coolant temp when cruising, but any type of idling or constant load will bring it to 10-20F higher than coolant. If heaving towing, the oil temp can go way beyond coolant temp, up to 285F under heavy load. The overtemp warning should be around 290F.

My oil tempature always run 20degree hotter once warmed up, towing (5,500lb Camper) or non-towing.

As for your transmission, you should be at around 185 after 10-15 miles of driving, up to say 195F-201F. I should never go much higher than that even when towing.

I need to double check but I'm pretty sure it takes more then 10-15 mile of non-towing for my transmission to warm-up to 185degrees non-towing. I just did some light trailering, utility cart, and transmission still read 194 +/- 7 gear 60 mph. Sometimes I was in 8th gear and it seemed that the transmission temperature would drop