Bad diesel fuel

[Cooter]

I use a cetane boost and have increased my mileage 2-3 mpg. I also use an injector clean. I add both of these at every fill up.
I have never experienced bad fuel, I change my primary filter on a regular scheduled basis. I have yet to experience any water when draining my secondary filter/ water separator. Additives are not cheap, but they are cheap compared to engine repairs.