High oil temperature?

[jetfixer320]

I know there are lots of discussions on here about high Transmission fluid temperature on the LZO's, but my question is a bit different. (I think)
I just took delivery of my 2025 Yukon LZO last week and took it out for a little "shakedown cruise" today.
On the gauge page it shows pretty much everything at mid scale (including the 199 trans temp) however...
Cruising down the freeway @ 80mph the oil seemed awfully hot (235-238F) which put it at about 3/4 scale.
ADMITTEDLY this thing is still very new (100 miles on the odo)
89F today and it was just me in the vehicle. NO towing.
Crawling around town at 35ish mph brought the oil temp back down to the 215-220F range.
I stopped by my stealership service dept and asked them, but only got shoulder shrugs.
Is oil temp this high normal?

 

[Marky Dissod]

Coolant over 230F, I've already pulled over; at high altitude, with an old coolant cap, coolant might evaporate.
As a mildly paranoid pessimist used to Dexron3, I treat ATF same as coolant, although Dexron6 is superior to Dex3,
can't hurt to treat Dex6 like Dex3.

Motor oil gets a lil bit less pessimism, it's meant to be hot enough to not have ANY H2O in it,
and (technically) it's not just a lubricant, it's also the other engine coolant besides the antifreeze.
Anything under 239F for xW30 motor oil is nothing to worry about, and that's for crude made of dino bone marrow.
Most synthetics can handle at least 257F sustained indefinitely, if the rest of the cooling system flows properly.

Most vehicles are made to aim for motor oil & ATF temps between 212F & 230F,
which minimizes H2O condensate by boiling it off and marginally improves MpG to achieve CAFE targets.

I do wonder if auxiliary motor oil cooling can be improved ...

 

[StephenPT]

I know there are lots of discussions on here about high Transmission fluid temperature on the LZO's, but my question is a bit different. (I think)
I just took delivery of my 2025 Yukon LZO last week and took it out for a little "shakedown cruise" today.
On the gauge page it shows pretty much everything at mid scale (including the 199 trans temp) however...
Cruising down the freeway @ 80mph the oil seemed awfully hot (235-238F) which put it at about 3/4 scale.
ADMITTEDLY this thing is still very new (100 miles on the odo)
89F today and it was just me in the vehicle. NO towing.
Crawling around town at 35ish mph brought the oil temp back down to the 215-220F range.
I stopped by my stealership service dept and asked them, but only got shoulder shrugs.
Is oil temp this high normal?

100% normal numbers. I see 220's to 230's while not towing and cruising on the freeway. Towing is in the upper 240's - usually around 250. I've hit 260 before, but that's when the ECM seems to be set to dramatically drop the coolant temp to get the oil temps down. Coolant likes to be in the 210-220 range if it can be, but it's apparent that the coolant control valve is holding it back and has capacity to open up and really cool things down in a hurry. When it does open up it doesn't take long and coolant temp is 180. Oil temp starts falling as well as that creates a large delta T.

 

[JayceeP]

Hot as you know what in Nova Scotia yesterday. I did a round trip 45 minute highway run in my 2024 XL SLT and getting off the highway my trans temp was 83C/181F and when I pulled in my driveway a few minutes later it bumped up to 87C /188F though it was sitting in the sun and idling for a few minutes while I wiped all the dead bugs off the front end.