I happened to check my oil temp after driving home from work yesterday. The outside temp was 43f, distance traveled was 5 miles at 50 mph. When i got home i inserted a digital therm and it read 140f. Oil used was Rotella 15w-40. I started out in a 70f heated garage at work, so the oil only heated up 70f in 5 miles. I will be changing to 5w-40 Rotella soon. I hope this helps. I think 140 is too cool of an oil temp. Isn't it?
By the way, in 75 summer weather after a hard ride with Amsoil 10w-40 the temps were 212f.
By the way, in 75 summer weather after a hard ride with Amsoil 10w-40 the temps were 212f.