Diesel Kleen is good stuff. I have used it in ALL my diesel engines for many years. (even before ULSD UltraLowSulferDiesel fuel was introduced to the market)
The increase in CETANE is proven to help diesel engines run better. The cleaning additives keep your fuel-injection system clean too.
Contrary to gasoline-engine additives.... Cetane boosters really help a diesel engine. Also, you should notice an efficiency improvement. (More hours per tank of fuel)
When using Diesel Kleen....
-- GREY bottle in summer. (more Cetane)
-- WHITE bottle in winter. (prevents gelling)