Been burning bio fuel for years. Started with a Rabbit conv. that i put a diesel in. Have burned canola oil , used french fry oil, used tranny oil, scented lamp oil, used motor oil, paint thinner (mineral spirits), power service and every possible mixture you can name. Did this starting with the Rabbit and on to two of my 240D,s and now in my 95 E300. YES it has all been filtered.
There has never been any bad effects. The engine is absolutely quieter. The fuel mileage does not change very much. Monitoring the filters is all thats required.
Just recently ran a tank full in 20 degree weather and had no problem. Gell additive always added at each fill up.
The last 240 I had is still running on original injectors and pump with 345,000.
