Operting temperatures

[Big BLU]

My TBSS ran at 205, I threw in a 160 stat and ran ~180. Worked fine. Cammed it and long tubes and was getting early 20 mpgs from less than 18 prior. Still not understanding this super hot drive trains are a good thing. I got the fluids deal. But the components and fuel economy.???

 

[SD Rebel]

My TBSS ran at 205, I threw in a 160 stat and ran ~180. Worked fine. Cammed it and long tubes and was getting early 20 mpgs from less than 18 prior. Still not understanding this super hot drive trains are a good thing. I got the fluids deal. But the components and fuel economy.???

From what an automotive engine engineer told me, most modern engines are designed to run at about 220F - 230F for the best overall performance and efficiency, that running them cooler actually reduces that efficiency.

My BMW for example has four cooling modes. The Eco mode keeps the coolant temp at 227F, most often at highway speeds at steady throttle. It's full cooling mode happens at stop lights and at idle, which is about 207F.

 

[Earl801]

OK, not entirely scientific, but this information may help. I had to run a few loads of gravel over the weekend, up a 6% grade for around 10 miles, where load weight estimated around 8,000 to 8,500 lbs. Ambient temp was around 40 degrees and I was in tow mode. I run Penzoil full synthetic and my 2019 Ram 1500 Laramie Sport has around 13K miles on it, powered by a 5.7 HEMI.

First Load

• Ran 4,200 RPM, which resulted in 60 MPH.
• Engine oil reached 260 degrees about 6 miles up the hill and held there.
• Coolant reached 225 degrees and held there.

Second Load

• Ran at 3,600 RPM, which resulted in 50 MPH.
• Engine oil reached 260 degrees about 8 to 9 miles up the hill and held there.
• Coolant reached 225 degrees and held there.

Third Load

• Ran 3.200 RPM, which resulted in 45 MPH.
• Engine oil reached 254 degrees at the top of the hill (and was still increasing prior to cresting the hill).
• Coolant reached 225 degrees and held there.

My conclusion is that, these engines are engineered to reach an engine oil temp 260 degrees and hold there, depending on the engine load requirements. At no point did the power derate, or the speed drop off, or any warning lights appear. I thought it was interesting, though, that the analog temp gauge didn't move at all throughout any of these trips. It stayed just left of center the entire time.

By the way, I have a boat with a GM Marine 6.2L Super Charged LSA. It doesn't matter what conditions I run it in, it runs at 210 degrees coolant temp. I don't have an engine oil temp gauge so can't tell you what that runs, but I think these newer engines just run hotter than older engines.

Hope this helps.

 

[jdefoe0424]

It's not just running at that temperature for maximum fuel efficiency...it does help though as the heat lost through the cylinder and head is less as temperature gradient is less.
It's also for emissions; combustion and cylinder temperatures and pressures have a pretty big effect on how complete the combustion process is and resulting emissions.

Sent from my Moto Z (2) using Tapatalk

 

[Krootz]

I almost had a stroke when I saw my dash after 100 miles in my new truck. Glad I came here and ran through the comments. Didn’t expect these temps to be normal

 

[User_3336]

Yeah, these engines run HOT! I've seen the coolant temp up to 226.

I almost had a stroke when I saw my dash after 100 miles in my new truck. Glad I came here and ran through the comments. Didn’t expect these temps to be normal

 

[User_3336]

Not a good idea. Then the active grille shutters would not be operating properly.

Can't we just throw in a cooler t-stat?

 

[Azhar]

Was around 225 degrees before the dealer update. Now at 204 degrees afterwards

What type of update? My coolant temperature reached 226 before the fan operate at high speed