I have owned 3 Dodge trucks w/Cummins engines and have never used any type of fuel additive. Put over 100,000 miles on 2 of them and not one fuel related problem. I always changed the fuel filter every time I changed the oil. We lived in Arizona, Oregon, Wisconsin and Tennessee so they have been kept in all types of climates, conditions and altitudes. Talked to several diesel techs about using them and they each thought they were mostly snake oil (their words not mine!!
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