I'm not saying it is good or bad, but when I used to work at a saw mill, I enjoyed hanging out for lunch in the mechanics shop. Forklift operators would bring their rigs in complaining about the smoke and running rough and it turned out they were putting hydraulic fluid in the fuel tank by accident.
The mechanic told them to suffer through it and burn it off, he wasn't doing anything about it. Those forklifts ran 24/7. He told me a diesel will burn just about anything but gas!