How much fuel does it use over an 8 hr period Bill?
I haven't ever measured it in any precise way. But I'm guessing less then one gallon in 10-12 hours. More important is the ability to heat the cargo area where I sleep without the extra wear on the idling engine. I'm positive it uses less gas in 10 hours then an idling engine uses. I really like the fact that I can park, turn on the heater from the drivers seat, go inside for a break and come out to a fully warmed up cargo area. This is only my first trip with the heater installed. Did it between Xmas and New Years Day. Guido could give you much better fuel consumption information. He's had a gasoline Espar for years now.
According to the supplied specs, it does use more fuel per hour then a diesel Espar, but again, gas is lower priced. And gas won't jell and stop the heater from working if you break down.