I am curious. Why do you need a block heater?

To get warm heat air sooner? To reduce wear on your vehicle, to make it last longer? Not to hear the valve taps for a few seconds (try synthetic oils, it helps).


IMO, Unlike cars of yester year, todays low compression, fuel injected cars start in almost any weather (down to short stints of
-40C), even if you are a bit shoddy in the maintainance. That is if you have a decent battery and electric charging system.