Wasn't sure where to post this and it really has nothing to do with horses or camping but I knew someone would have an answer for me....I am looking for a heater to use in my truck that doesn't run off my truck battery or need propane...Someone told me they do make a heater like this but I can't seem to find one anywehere....I need it for work this winter, cuz I work as a security guard and need to be in my vehicle  and someone told me it is hard on your vehicle to run it constantly or to be starting it and shutting it off all the time...By the way my heater in my truck works great, just wondered if the last two things I was told were really true...

You want an Espar Heater. Its what they use in semi trucks to keep them warm.

They have various products that either focus on keeping the coolant warm ( so the engine is ready to go)or in keeping the cab warm by heating air and circulating it.

They will run all night for $1 of diesel fuel.  Cheaper than keeping a big rig idling all night.

http://www.espar.com/html/applications/truck.html

Sorry Paul, Didn't see you already posted that.