How hot is too hot?

[Shawn Burns]

265 is nuts IMHO. Things you can do in easy-to-harder order
- remove all but two rows of slats in your active grill shutters (more airflow to the rad at all times)
- put in a 180F thermostat
- tune your fan to come on sooner
- install oil cooler

I've done the first two, and althought those by themselves won't reduce your peak temperature, they will help in that it takes longer to get there now. So if you used to see 265 peak after a 2 minute climb/grade, maybe you only reach 250 now at that same spot/load.

There have been oil coolers recommended on here, ones that come with there own thermostat. You will definitely need a cooler or at the very least tune the fan to come on sooner and I'd definitely do those first 2 as a first start.

Also make the switch to 5w-30 high quality synthetic oil (PUP, valvoline extended performance, amsoil, redline). I hit about the same oil temp when I first purchased the truck on my first trip while towing. I never saw those temps again (however still higher than I'm comfortable with) after the viscocity change.

I now have everything that famffml recommended + the caulk transmission thermostat delete. I rarely get to 220 any more.