IMHO, de-odorized mineral spirits are even cheaper than diesel fuel and far easier to ignite than kero or diesel. Think charcoal starter - that's about how it ignites and burns. Not a big explosion hazard like gasoline or lighter fluid but far easier to ignite than diesel.

It has another use in your vehicle - that is the solvent of choice for parts washers in much of the country (prol not in So Cal). Wet a rag/paper towel with it, wipe off hands, oil caps, etc. Takes the fat out of your skin, but not as aggressively as gasoline - a little hand lotion afterwards works great.

Kero sneaks past seals over time and spills STINK for about half of eternity. If you spill mineral spirits, they evaporate fairly soon (minutes to hours, depending on conditions), leaving no odor. I speak from experience in vehicles on both counts...

Tom