42126 Mercury GUIDE

Fill the fuel tank at the end of each day of operation to drive out moist air and to prevent condensation. Do not fill the tank to the top. Fuel expands as it gets warm and may overflow.Do not fill fuel filters with fuel before installing them. Contaminated fuel will cause accelerated wear to fuel system parts.
Fuel Recommendations
Use only fuel as recommended in this section. The fuels recommended for use in Caterpillar engines are No.2-D diesel fuel and No.2 fuel oil, although No. 1 grades are acceptable. The following fuel specifications are some of the worldwide fuels which also meet the requirements. The following fuel characteristics should be considered when procuring fuel for use in Caterpillar diesel engines. Caterpillar Diesel Engines are capable of burning a wide range of distillate fuels. The use of clean, stable blends of distillate fuel which meet the following requirements will provide quality engine service life. Cetane Number
The minimum cetane number required for average starting conditions for the direct injection engine is 40. A higher cetane value may be required for high altitude operation or cold weather starting.Filterability
Clean fuels should have no more than 0.1% of sediment and water. Storage of fuel for extended periods of time can cause fuel oxidation with solids forming, causing filtering problems.Pour Point
The pour point of the fuel should be at least 10°F (6°C) below the lowest ambient temperature at which the engines must start and operate. The lower pour point of No.1 or No.1-D fuel may be necessary in extremely cold weather.Cloud Point
The cloud point should be below the lowest ambient temperature at which the engines must start and operate to prevent the fuel filter elements from plugging with wax crystals. Refer to topic, Fuel Problems in Cold Weather Operation, for additional information.Sulfur
Fuels containing 0.5% or less sulfur may be used with recommended crankcase oil drain intervals using API CD, CE or CF-4 performance oils. With sulfur above the 0.5% level, use API CD, CE or CF-4 oils with an ASTM D-2896 Total Base Number (TBN) of 20 times the fuel sulfur for normal oil drain intervals. Regular oil analysis (S O S) will provide information to monitor oil properties and engine wear metals to maintain successful engine protection and establish oil drain intervals.Viscosity
The viscosity of any fluid is a measure of resistance to flow. Fuel viscosity is important because it provides lubrication for fuel system components and also its effects on fuel atomization. The viscosity limits have been provided to meet both of these effects.Additives
Fuel additives are generally not recommended nor needed for the specified fuels listed. Cetane improvers can be used as necessary for the direct injection engine requirements. Biocides may be needed to eliminate microorganism growth in storage tanks. In cold conditions, treatment for entrained water may also be necessary.Consult your fuel supplier about the use of additives to prevent incompatibility among additives already in the fuel and the additives to be used. Other fuel types may be burned in the engine when economics or fuel availability dictate. Consult your Caterpillar dealer for more information and advice on any specific fuel.Fuel Sulfur Content
The percentage of sulfur in the fuel will affect the engine oil recommendations. Fuel sulfur is chemically changed during combustion to form both sulfurous and sulfuric acid. These acids chemically attack metal surfaces and cause corrosive wear.Certain additives used in lubricating oils contain alkaline compounds that are formulated to neutralize these acids. The measure of this reserve alkalinity in a lubricating oil is known as its Total Base Number ( (TBN). TBN values are essential to neutralize the acids from combustion gases and to minimize corrosive wear.Any API classification performance oil should have sufficient TBN for fuels with less than 0.5% sulfur. For fuels with 0.5% to 1.5% sulfur by weight, new engine oil must have a TBN of 20 times the percentage of fuel sulfur as measured by the ASTM (American Society of Testing Materials) D-2896 method. (ASTM D-2896 can normally be found at your local technological society, library or college.)For fuel with sulfur exceeding 1.5% by weight, use an oil with a TBN of 20 and reduce the oil change interval by one half. Fuels containing 0.5% or less sulfur may be used with recommended crankcase oil drain intervals using API CD, CE or CF-4 performance oils. Fuels with sulfur above the 0.5% level, use API CD, CE or CF-4 oils with an ASTM D-2896 Total Base Number (TBN) of 20 times the fuel sulfur for normal oil drain intervals.Regular oil analysis (S O S) will provide information to monitor oil properties and engine wear metals to maintain successful engine protection and establish oil drain intervals. Caterpillar recommends infrared analysis (in conjunction with wear metal analysis) of used oil in determining the effectiveness of oil TBN and acid neutralization. The Caterpillar dealer S O S program provides this information.Periodically request fuel sulfur content information from your fuel supplier. Fuel sulfur content can change with each bulk delivery.For more information on fuel selection and fuel properties, refer to Diesel Fuels and Your Engine, SEBD0717. For more information on oil, fuel sulfur content, etc., refer to Oil and Your Engine, SEBD0640 or contact your Caterpillar dealer.