Kerosene and jet fuel (essentially same cuts) are the next lighter cuts above diesel and # 2 heating oil (essentially same cuts) off the crude distillation units in refineries. Old timers in Vermont have used 50/50 kerosene/diesel in their diesel cars and tractors in the winter for years. The kerosene keeps the diesel from gelling. Your fuel economy will be a little less with the kerosene because it is a tad lighter in specific gravity. Other than that, you likely won't notice any difference, with as much as 50% mix. I wouldn't use it straight, but it would likely work okay.
For those who want to debate kerosene vs. jet fuel or diesel vs. heating oil. These have slightly different specs from each other but can be the same if the particular crude they get them from matches specs on all. Generally though, refiners have to juggle cuts a little bit on the stills or segregate virgin (direct crude source stuff) and cracked (off crackers that convert heavier-boiling stuff to gasoline) stuff to blend to specs. Some crudes, etc. may require some additional processing to get specs on jet fuel or diesel instead of kerosene and diesel.
Ralph
