How long do you need to plug in your engine block heater before you can unplug, start your car, and be on your way? To save energy and money this winter, I plan to put mine on an automatic timer but I need to know how long to set it for. Is 20 minutes enough?

Engine block heater - how long does it take to warm up?

Caddyman November 30, 2007, 10:53pm 3

How many watts is the heater rated for?? A 1200 watt heater will do the job in an hour or a little less…