Diesel fuel is rated not by octane number but something called a cetane number. The cetane number gauges the ease with which the diesel fuel will autoignite when compressed. Higher cetane numbers indicate easier self-ignition and better engine operation, whereas a higher octane fuel would be more resistant to self-ignition under compression.
A numerical index designed to reflect the ignition quality of diesel fuels. The cetane number reflects the percentage of cetane in cetane/x-methyl naphthalene blend equal in ignition quality to a specific sample of tested diesel fuel.
Measurement of the ignition quality of diesel fuels. Higher cetane numbers provide a shorter ignition lag (better ignition quality). Cetane number is measured by a single cylinder engine in the laboratory.
Measure of ignition quality of a diesel fuel. The higher the Cetane Number, the easier a high-speed, direct injection engine will start, and the less "white smoking" and "diesel knock" after start up.
A measure of ignition quality of diesel fuel. The higher the cetane number the easier the fuel ignites when injected into an engine. Cetane number is determined by an engine test using two reference fuel blends of known cetane numbers. The reference fuels are prepared by blending normal cetane (n-hexadecane), having a value of 100, with heptamethyl nonane, having a value of 15.
A measure of ignition quality of diesel fuel. The higher the cetane number, the easier the fuel ignites when it is injected into the engine.
A measure of how well a diesel fuel will ignite, and how much white smoke and knock will be produced.
Measure of fuel ignition characteristics. Like the octane number used for gasoline, the higher the value, the better the fuel performance. A higher cetane number correlates with improved combustion, improved cold starting, reduced noise, white smoke, HC, CO and particulate emissions particularly during early warm-up phase. The EPA uses this parameter as a measure of aromatic content in fuel. Typical Cetane numbers around the world are as follows: Europe: 43 - 57, average 50 U.S. lower, minimum 40, average 43.
A measure of the ignition quality of diesel fuel that indicates the tendency of the oil to ignite spontaneously under pressure, which is a desired characteristic for diesel engines but not for gasoline engines.
Comparison of the ignition quality of diesel fuel, Cetane and alpha -methyl-napthalene are both hydrocarbons but alpha-methyl-napthalene has very poor ignition quality while cetane has good ignition quality. After mixing them together, adjustment is made so that it has the same ignition quality as the diesel fuel being tested and the cetane number, given to the diesel fuel, is the percentage of cetane in the mixture.
Cetane number or CN is a measure of the combustion quality of diesel fuel via the compression ignition process. Cetane number is a significant expression of diesel fuel quality among a number of other measurements that determine overall diesel fuel quality. Cetane number is actually a measure of a fuel's ignition delay; the time period between the start of injection and start of combustion (ignition) of the fuel.