ENGINE AR-COMPL 10R9819 - Caterpillar

Modification Of Fuel Characteristics
CETANE NUMBER: The cetane number of a fuel can be changed if the fuel is mixed with a fuel that has a different cetane number. Generally, the cetane number of the mixture will be in direct relation to the ratio of the fuels that were mixed. Your fuel dealer is the best source of cetane information.
A different method to improve the cetane number of a fuel is with the use of additives. While additives will increase the cetane number of a fuel as measured in a cetane test engine, the fuel characteristics when an engine is started in real conditions are not necessarily the same as those of a natural product with the same cetane number.
CLOUD POINT: Additives have little or no effect on the cloud point of a fuel. One method to lower the cloud point of a diesel fuel is to mix it with a different fuel that has a lower cloud point, like No. 1 Diesel Fuel or Kerosene. The efficiency of this method is not good, because the ratio of the mixture does not have a direct relation to the improvement in cloud point. The percent of low cloud point fuel that must be used increases more than the cloud point is lowered. The illustration shows a chart that can be used to find the necessary mixture for two fuels with different cloud points. To use the chart in the illustration, it is necessary to know the exact cloud point specification of each fuel to be mixed. This specification can change from one purchase of fuel to the next, and is normally available from personnel at the source of the fuel supply. This method can not be used to prevent cloud point problems when lower cloud point fuels are not available.
Generally, the most practical method to prevent problems caused by fuel cloud point at low temperatures is the use of fuel heaters. In most applications, these can be used at lower cost than fuel mixtures.
POUR POINT: The pour point of a fuel can be lowered either by the use of additives or by a mixture with a lower pour point fuel, as given in the paragraphs for "Cloud Point". As with the cloud point, use of a mixture does not give good efficiency or low cost. The same chart shown in the illustration for cloud points can be used for an estimate of pour points, if the fuels do not have additives which change the pour point.
Chart to find approximate cloud point of fuel mixtures.Additives are a good method to lower the pour point of a fuel. These additives are known as "pour depressants", "cold flow improvers", or "wax modifiers", and will permit fuels to flow through pumps, lines and hoses when used at very low levels of concentration. It is important that these additives be completely and thoroughly mixed into the fuel at temperatures above the cloud point of the fuel if they are to have an effect. They will