DP isn't snake oil in my view. It's a powerful, high-cetane solvent mix that dissolves carbon and petroleum-based crud. VO is known to cause all kinds of problems and waxy residues in the fuel system is one of them. As I've said before, if you're concerned about the environment, use biodiesel. Just a suggestion.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL