Andy, learn from my experience. The Espar heater is without a doubt the most useless and extravagant purchase I have ever made. It fails so often it cannot be relied upon as an engine pre-heater. It is ridiculously expensive to purchase and install and very complicated to repair. Dealer support is the worst. Keep in mind the more gadgets you install on your vehicle, the more time you will have to spend troubleshooting and repairing them, and believe me you WILL HAVE TROUBLE WITH THE ESPAR. Its just not worth it.