According to LoveToKnow and Amazon.com, the best diesel fuel additive is Stanadyne Performance Formula. Stanadyne stands out because of its performance in independent tests and is approved by equipment manufacturers such as General Motors, Ford, and John Deere.
LoveToKnow lists AMSOIL Diesel Concentrate as the second-best diesel fuel additive based on its system cleaning and lubrication abilities over different types of engines. Since the additive compensates for different qualities of diesel fuel, it brings out the best engine performance for a wide range of vehicles.
Amazon.com, LoveToKnow and Fuel and Friction include Power Service Diesel Fuel Supplement Plus Cetane Boost among their top rated diesel fuel additives. According to Fuel and Friction, this additive is effective at cleaning dirty injectors and boosting cetane ratings by up to six points. The additive also lessens fuel consumption by enough to typically make up for the cost of the additive. In addition, it protects pumps and injectors from the wear and tear of low-sulfur diesel fuels.
While Fuel and Friction points out that most additives excel in one particular thing, it suggests CleanBoost Maxx Super Concentrate Fuel Supplement as an alternative all-rounder that also takes care of carbon deposits, a feature not offered by other brands.