At the last Benz club meeting, one of the guys there said he tried it. It caused some of the rubber seals to break down. You should check with your dealer/manufacturer whether the parts can take biodiesel. I'd like to try it. There's a place supposedly that has some over the hill (Shenandoah Valley) from us.
Another guy told about his daughter collecting cooking oil in various containers and taking it out to her apartment parking lot and pouring the stuff in her Benz diesel. A guy was watching incredulously as she poured the stuff in, started the car and drove it away.
Ralph