AMSOIL Diesel Concentrate and
AMSOIL Diesel Concentrate with Cold Flow are some of the better additives on the market when it comes to lubricity.
Running 2 stroke is the best thing for the HFRR (lubricity) rating in fuel, but 2 stroke oil doesn't give you fuel detergency, stability, anti-gel qualities, etc. In my 2002 Dodge Cummins, I run AMSOIL Diesel Concentrate (and Diesel Concentrate with Cold Flow in the winter) and I add in
AMSOIL Interceptor 2 stroke oil for added lubricity. I do this because 1998.5 - 2002 Dodge Cummins trucks have the Bosch VP44 injector pump that is especially sensitive to fuel HFFR ratings for injector pump survival.
The lower the HFRR number, the better your lubricity. This chart was taken from mopar1973man.com (Michael Nelson). Michael is a guy who is a big proponent of 2 stroke oil in diesel fuel as a lubricity improver. I've had many good conversations with Mr. Nelson and agree with him on most points. I contend that while 2 stroke oil DOES add lubricity, it doesn't do much for gel point, and it does nothing for detergency. Keeping your fuel system and injector nozzles clean is important to mileage, power, and to keep from scorching pistons. That's why I run AMSOIL Diesel Concentrate as well as AMSOIL Interceptor 2 stroke oil. I get fuel stability, anti-gel, detergency, and ultimate lubricity. I've been running this combination of additives for years now with perfect results.
Running 2 stroke in diesel fuel is against all manufacturer recommendations. No manufacturer will tell you to run 2 stroke oil in diesel fuel, since that use is inconsistent with the labeling and intended purpose of 2 stroke oil. But the facts on HFRR speak for themselves. Also, I don't recommend running 2 stroke oil in any diesel engine that is designed to run ULSD fuel. Lubricity is mostly a concern for diesels that were designed to run on LSD and HSD fuels and that can be damaged by the commonly poor lubricity ratings of ULSD fuels.
