Some other advantages of oil heat in your garage:
1) Areas like mine have natural gas expansion going on everywhere (except to my house apparently which is another sore point to me). In those areas, used oil tanks, and used furnaces can often be had for nearly free... in some cases, they are informally selling/giving away the oil as well.
2) Ease of fixing.
3) Less chance to blow up than with propane.
4) Older furnaces are often quite literally, bombproof.
Disadvantages:
1) Insurance costs
2) Priming (if it is a hanging it adds extra pain)
3) Air purging
4) Setting air mixture ratio
5) Cleaning
6) Operating cost is tied to the whims of foreigners who will greedily accept our money, then use some of it to to wage jihad against us. (and the remainder to fund lavish lifestyles that British monarchy, US Presidents, and Canadian Prime Ministers can only dream of while other western ex-pats conduct the real work of getting it out of the ground around the world)
My views aside, I can see alot of the reasons why people move to propane, and I want to in alot of ways, but for now, oil furnaces are just too common for my area. I do plan on upgrading this beast to a used newer house furnace eventually when it finally puff's out.
R