Yep, I have one installed. The only thing i woul change is adding an aux tank to hold #1 fuel. I really would rather run higher quality fuel in the winter.
Usage? I set the timer if overnight temps are in the 30's°F or colder. 30's°F overnight here means the daytime temps were not good so the fuel and engine are staying cold. You have to learn the amount of time to run the heater. I use no less than 20 minutes and increase to the full 120 minutes. Tonight, they forecast around 5° F low so I set it for 04:30 and usually crawl my butt out to start the Cummins around 05:50. That is more than enough to get it warmed. I go with that cycle for +10°F to -10°F After it gets below -10°F the cycle increases fast. By the time I hit -20°'F or more overnight, the cycle is a full 120 minutes.
The 1/8" fuel line on the Espar gells easily. You need to run a lot of additive or blend heavily. Additive alone does not work after about 0°F.
Watch the batteries. he Espar is easy on fuel consumption, but really draws on the batteries. I make sure to run the truck at least 20 minutes after running the Espar. If you run less, a trickle charger is a good idea.
I will give up my Espar when they pry my cold, fuel gelled fingers from it. There is something really nice about a warm truck cab after work on a really cold day.
;-P TMTT