Myself and a few of the newer insight owners decided to get one for more MPG and to avoid driving 5-7 miles or worse, idling for 15 minutes for heat. Like the AC, the heat is also hybrid, half warm and runs down the mpg and prevents EV mode.
Its 400 watts. If you left it plugged in for 8 hours you got heat and the cold engine light wont light up, but thats a hell of a lot of waste. We find its most efficient to plug it in for 2 hours before driving and that warms up the enbgine 2 miles or about 2 minutes quicker.
I got a katz 800 watt one I am going to try this winter. Yes, there is a plug about the size of a half dollar with a hex on it to remove for the block heater. This isnt a freeze plug not the block drain bolt. You got to remove the splash guard, belly pan and reach around behind the passenger side firewall under the car to get to it.
