[bestclimb]

Originally Posted by MetroMPG

Ask and ye shall receive!



From: Experiment: how long should a block heater be plugged in? - MetroMPG.com

I haven't tried to measure impact on fuel economy because I didn't think I could control enough variables to get meaningful results.

What do you think about letting the car cool to ambient over night, and check the mileage from a cold start over known course? Then do it again once the car is up to running temp. May not be total accurate, but over the course of a couple mornings you should see a pattern.

How consistent is the first 5 to 10 miles of your commute?

One other argument for using a block heater (and or oil pan) is that the oil flows and splashes better when warm this means oil coating your cylinder walls quicker, to your bearings quicker, and bathing your valves quicker. Which means your engine going to last longer. On some mornings it also means your engine will start at all.