Cetane Number
WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The cetane number relates to the auto-ignition quality of diesel fuel. The rating applies to diesel fuel similar to octane rating for gasoline. A measure of how readily diesel fuel starts to burn (auto ignites) at a high compression temperature. Diesel fuel with a high cetane number auto-ignites shortly after injection into the combustion chamber and has a short ignition delay time. Diesel fuel with a low cetane number resists auto-ignition and has a longer ignition delay time. A minimum cetane of 40 is required for a optimal driveability and performance.