Under the poll above, there was a field for checking used motor oil. I call used motor oil black gold. I see that 8 of us checked the box, so I'm guessing at least 8 of us use black gold. What kind of experiences have you guys had burning the stuff? I've been doing it for quite some time, and have learned quite a few things. First, it has to be pretty hot outside 70 degrees or above to burn the stuff straight. I fried my pump last winter trying to burn straight black gold. In the summer, I dilute mine down with 20% gas. In the winter, I dilute it down with 30% gas. Second, filter filter filter. I used to just pump or pour black gold into my fuel caddy and then pump it into my vehicle where the only filtering was my pickup fuel filter. The problem with this is the diesel fuel filter on my pickup is quite a bit more expensive than those I can put on my pump. I was changing fuel filters every 1000 miles. So, now I filter the oil as it's pumped into my fuel caddy. I filter the oil when it's pumped into my pickup. Then, finally my fuel filter in my pickup is the final stage for filtering. It sure has prolonged the life of the fuel filters of my pickup.
I started burning black gold because it's virtually impossible to find waste vegetable oil. I'm from a rural area, and there aren't that many restaurants. The few that there are already are selling their waste vegetable oil to other oil burners. Nobody is willing to put black gold through their vehicles, so there was my niche. Some people actually even are willing to pay me to come pump out their black gold. The other reason I like it is I didn't have to put heaters and such in my tanks like WVO. Really, I haven't made any modifications to my pickups at all other than just one. Black gold burns hotter and longer than diesel. I advanced the timing on my pump 1 tooth making the pump shoot black gold in sooner than stock. If and when I ever run on straight diesel, my pickup will pop off a bit like a race car does. When it's on black gold, it's as smooth as they come.
I've put between 30 and 40 thousand miles on my oil burners using black gold. Amazingly enough, there has been little to no change in the amount of miles I can get out of a gallon of fuel. My pickups do start a bit harder on it than diesel, and they do tend to smoke a little more especially under a big load. Other than that though there is little to no change from burning straight diesel. The good thing about these old 7.3's is the fact that injection pumps are cheap (under 300 bucks) and injectors are cheap (full set of 8 for under 200 bucks). Even if you screw something up, it's not going to cost a lot to fix it.
I like the ideas of biodiesel, and used motor oil, and just as well using propane in gas engines. I like used motor oil though. For any of us that own a shop, its decently easy to get our hands on really. But, it would have to be filtered, and filtered very well. The injector tips are very small, and the filters go down pretty far in microns as well.