When I lived in Alaska I lived by my block heater. Couldn't live without it. Now that I live in Arizona I only miss it once and a while. This winter there have been a couple dozen mornings with temps below 20 degrees (I'm in the mountains) and with my short commute, my Disco II isn't really "warm" by the time I get to work.

Is the Genuine LR Block Heater really effective? I forget what I had installed on my Jeep in Alaska, but I know it was more expensive than LR's $115 kit.

 

Living in Colorado I see every morning as cold, I do not run a block heater. I start it up, give it 60 seconds and I am gone. Starts easy, no performance problems, but I do change the oil at 2000 mile intervals during the winter do to the rich run cycles.
Mike