It also matters who the wholesaler is for the base fuel stock. The additives make it brand specific. If the store in question is buying cheap base stock, you can expect crappy fuel quality. Truck stops are your friend, the busier, the better. Less chance for water to be sitting in the fuel tank and a quick turnover. Truckers can't afford crappy fuel, it kills their mileage and kills their rigs.

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Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]