quote:
Originally posted by 1 FMF:
I say it doesn't matter, as long as the engine runs smoothly and has power to move the car.
Consider this: what's more important, coolant temp or oil temp, in regards to an engine being warmed up? I have an oil temp gauge on my car, 2002 camaro LS1 V-8. Typical American pushrod V-8, 6qt oil capacity, except it's aluminum block & heads.
This past summer, on a cold start the oil temp would be 70-80 deg F, and slowly get to 200+F long after the coolant temp guage is running at 190-210F. With mornings now around 50F, and even though I garage my car and start out at 60-70F oil temps, the car can be fully warmed up coolant-wise to 190F after having driven about 8 miles and for about 15 minutes and oil temp will still be around 100-110F. I'm curious to see how long a drive it takes to get oil temp to 180+ deg F this winter after the car has been sitting outside at 32F and below.
With this info in mind, I would think anyone who lets their car run 20 minutes in the winter to warm it up is not helping it any. Coolant temps may be hot, but oil temp certainly won't be. And a gas engine idling with cold oil temps for an extended period can't be good. At the very least they are wasting gas.