I left the block heater plugged in over night. I figured it consumes about 30 cents worth of electricity doing that.
But in the morning I had frost on the roof of my house even though ambient temp was supposedly around 40°F.
I keep a small scanner in the glove box and I plugged it in to see coolant temp. ECT was 100°F to start my morning commute vs. I guess it would've been 40°F without the block heater.
The green cold coolant light went off in 0.5 miles from my house vs.2.5 miles on a cold morning like this. (I make it my goal to keep that green cold coolant light on as long a distance as I can from my house because even it seems contradictory I think it means I covered a longer distance on less fuel if it is still green at a certain waypoint than if it already went off before that point!?)
At the end of the first road I take (3 miles from house) I like to see the display just over 60 MPG.This morning it said 74.3 MPG!
Then I have to take a highway where I have to pick up the pace to match the speed of the 'wild idiots'
where the MPG will drop until I get close to a town again but the block heater really gave me good head start so to speak.
When I get to work on a cold morning I usually see 60-62 MPG displayed and today it said 69.9 MPG!
(on a saturday with little traffic I am always 70+ despite the cold so still traffic/speed is the biggest MPG killer)
Besides the MPG it is better for the engine not to have to fight the cold!
Why did I not do this sooner? Thanks again for the info posted here guys!