FWIW...Im a full time RVer and where I am parked electricity is free. Unfortunately the wiring in my RV wont allow for me to run a space heater otherwise I would. One of the ways I warm my humble abode (22ft 5th wheel) is I use a couple of the 250 watt heat lamps in the brooder lamp fixture rated at 300 watts. In temps down to about 25 degrees it does a fair job of keeping the chill knocked off the place after running my propane heater long enough to get the place up to temp. The problem I see with this route for your application is the ability to power them without killing your vehicles battery. Unless you have auxillary batteries and a way to charge them daily your going to need to plug in some place.<div><br></div><div>I think a better option for you may be to do as previously mentioned and buy a couple of oil lamps. I would forego the cheaper metal and glass ones at Wally World and use the more expensive all glass ones for a couple of reasons from the candle section at Wally World. These things can kick out a pretty good bit of heat. I keep a couple around for emergencies should we loose power. And yes I have a small grill that will fit over one with the globe off and I can cook on it too if need be!</div><div><br></div><div>1st, you can see how much oil to put in them without over filling them. Cant do that with the cheaper metal ones. These do cost about twice as much though but for the simple fact I can see how much fuel to add is well worth the added cost. I also think these models are a little more effceint at creating more light and heat on the same amount of fuel too.</div><div><br></div><div>2nd, the fuel is pretty easy to store and purchase. If buying the lamp oil is too expensive for you, you can use Kerosene in them and that will save you a couple bucks a gallon. This is only if you can go to a gas station where you can pump Kerosene to fill your container. Buying it in the 1 gallon bottles or 5 gallon cans at Lowes is ridiculas price wise. To combat the Kerosene smell which isnt bad when properly adjusting the wick, you can go to Lowes and get some scent to add with the Kerosene.</div><div><br></div><div>While a vehicle isnt as tightly shut up as most homes, you may still want to slightly crack a window or a vent to prevent toxic gases from building to unsafe levels. I lived in Japan for 12 years and this was the primary method of heating a home and while occasionally there would be a news report of a family suffering CO2 poisoning, it was a pretty rare occurance considering the number of homes heated this way every night during the cooler months of the year.</div><div><br></div><div>Another option would be to use one of those small catalytic heaters that run off propane that people often use to heat a tent in the cooler camping climates and hunting blinds. These use the 1 lbs bottles and will run about 6 or so hours on one bottle. I use one of these at the deer lease in conjunction with the adapter kit that allows for a 20 lbs bottle to be hooked up to it. The small one is very compact, reasonably priced and can be bought at just about any camping/hunting store. It cost about 15 bucks to refill this tank, so that might be an option too. I am able to heat my RV, provide hot water needs and cook on a 20 lbs bottle about 5-7 days per a fill. Again with this system you may want to slightly open a vent to prevent the chance of toxic gas building up to unsafe levels.</div><div><br></div><div>Just some things to consider from someone who has actually used these methods for heat at times.</div>