Does fuel lubricity make that much of a difference on a MB? I know it does on a car with a VE pump, but I don't know how much of an inline pump is lubed by the fuel.

When I got my best economy ever in my TDI I was running B15 (56.8 MPG!)

-J

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.