Oil Temp & Coolant Temp - Which Is More Important?

[WOT]

The oil will still function as intended by the designers all the way up to around 260F. Mobil 1 doesn't actually break down until around 400F. Your coolant system will not function at 260F.

So, if you oil is getting hot, it is really just thinning out a bit. If your coolant temp is getting hot, it is causing your bore clearances and head to block dimensions to change radically.

A motor that has coolant temps in the 250-300F range will warp the heads, blow out the head gasket, and scuff the bores (and eventually seize). If you oil is getting this hot, it won't necessary systematically detroy the motor, but you have a problem somewhere.

If my oil temp ever gets into the 230 range for sustained periods (due to pulling a trailer 8hours a day or whatever), I would change the oil to a higher viscosity (20w-50), plus probably add a high temperature viscosity improver.

If the oil just occasionally gets hot and cools down, no problems.

With my 170 stat and reprogrammed fans, my oil never gets above 210 even in the dead heat of Texas summer when I am out racing around.

 

[Jfireboy1]

My oil temps I think run hotter than the coolant due to the fact that the oil run through my turbos to cool them down! i only use mobil 1 full synthetic. if im driving highway speed my oil temps seem to run around 10 degrees hotter than my coolant but i think thats cause my turbos are raising the temp being that the oil passes through them. the minute im doing city driving the oil temps come down even with coolant at around 200

 

[Carlwalski]

it's a month old and you had a C2 Autometer gauge in the first post.

This is an older thread of mine is what I meant sorry, 4 weeks and it was time for an update on how I got on, I said I would update.

Thanks to everyone for your help and input in getting my trucks temps down.
In the end it was just a new tune that was needed to run the fans earlier.


Cheers!