Inconsistent fuel filter life is a problem that continues to plague most heavy-duty diesel fleets. It has been proven that fuel filter life can be strongly influenced by the thermal and oxidative stability of diesel fuel that is being filtered. Filters consistently exposed to diesel fuels that produce a tar-like substance in abundance upon heating (sometimes termed “asphaltenes”) will plug far more rapidly than filters exposed to diesel fuel that does not easily form these tar-like substances. Fuel additives have long been used to maintain fuel system cleanliness and to improve diesel fuel stability. It follows logically that such additives could have a positive impact on fuel filter life by maintaining the cleanliness of the fuel filtration media. This paper reviews the laboratory evaluations and field tests that were run to compare fuel filter life in both the presence and absence of diesel fuel additives. Both laboratory and field results show a substantial fuel filter life improvement with the consistent addition of a proprietary additive to diesel fuel systems.