High-speed diesel fuel has a higher cetane number than fuel for low-speed, stationary engines. The cetane number of high-speed diesel fuel is typically around 50. Cetane numbers for diesel fuel range from 40 to 55, according to the Louisiana Department of Natural Resources. High-speed diesel fuel is also classified as 1D or 2D, indicating pour point and viscosity.
A higher cetane number is not a measure of fuel quality, according to GlobalFinest.com; it just indicates that the the fuel will ignite more easily. It takes less time between fuel injection and ignition, a desirable quality for higher speed in a diesel engine.
Pour point refers to the minimum temperature at which the fuel will flow, while viscosity measures its resistance to flow. A 1D fuel, which has a lower pour point and less viscosity, works better in low temperatures. A 2D fuel, with a higher pour point and more viscosity, is more suitable under warmer conditions.
2D fuel maintains its lubricating qualities at high speeds. It also contains more BTUs (British Thermal Units, a measure of power), produces more power per gallon and reduces consumption, according to the Louisiana Department of Natural Resources. The fuel requirements for a specific diesel engine typically appear in the owner's car manual.
