BP Ultimate Diesel has Cetane rating of 52 whereas the Australian Standard for diesel is 46 cetane. If you look into your car specs (TDI's) you'll see a note underneath max power that is based on 51 Cetane. The European standard for diesel is 51 Cetane. BP Ultimate Diesel has 1/5 (one fifth) of Sulfur compared to others which produces less soot. Better for DPF. For me only BP Ultimate in my TDI