Back in October I had a problem with my '92 E300D (180,000km 110,000m). My car stalled on the road. Had the problem fixed by a diesel injection system specialist. The O-rings in the fuel succioning mechanism (dont know the name of this part) were replaced, air was sucked and the fuel would not go in the engine, that I understood.
After I asked him if an additive would prevent such a problem, this guy recommended Stanadyne, Performance Formula to be added in the tank. I've been adding this product since, and I figure that there is a fuel economy that more than covers the cost of the product.
Anyone use it, or know the product?