[MichiganMat]

I saw this same situation with my SC engine:

15-40: car never got over 180 with trombone cooler except under extreme 20min redline hill-climb circumstances
20-50: car was into 210 in traffic with an updated radiator cooler with fan.

I've chimed in more than once on this board to threads where owners are wondering why after an oil change their car is suddenly running 30degrees hotter. "Did you go to 20-50?" Answer is %95 YES.

I still run 20-50 but unfortunately it was changed about 100 miles ago.

Im also suspicous about using oil data as suggested from 20 or 30 years ago. Have there not been major improvements in oil technology since then? Take me to school...