I killed my W210 E300TD non CDi with a relatively conservative blend of vegetable oil and diesel. It was a high miler (>200Kmiles) and almost straight away developed leaks in a seal in the fuel pump and in the fuel lines. Cost me almost a grand for a new fuel pump 2nd hand plus an independent to fit it.
If you search for my previous posts you will see reference to this. Not saying it will happen to you, just that it happened to me!