Saw the craziest thing at the dump the other day.

[NightSniper]

I was dumping off my trash over the weekend, the guy next to me was in a ford diesel truck. He was almost done and he noticed I threw out a gallon jug of used canola oil. He asked if he could have it and I gladly gave it to him. He walked over to his fuel tank and poured it in except for a little bit in the bottom which had some french fry floaters in it. He said that the truck would burn it like diesel fuel and would help lubricate his engine. I asked if it was converted for bio diesel and he has no.

Was this guy off his rocker or will a stock diesel truck burn cooking oil like that?