There will be no diffrence between B5 and ULSD, or off-raod diesel or just regular **** diesel. The truck dosnt know the difffrence between the fuels. Its the longevity of the fuel system that has many questioning when these trucks are run on low grade diesel or B5. Performance will be there, some just dont know how long will the fuel system take the abuse. I run off-raod diesel in my 6.4 with no problems yet, and I personally feel that the fuel system is stout enough to handle low grade fuel. The injectors, fuel rails, fuel pump, and lift pumps all were made to handle the abuse. ULSD is just emissions propoganda. Saying the truck will burst into flames and spontaneously combust if you run anything other then ULSD is hogwash. All about protecting the earth by charging everyone more money

Cowboy Steve