FUEL AND OIL SPECIFICATIONS
wear due to acid build-up in the lubricating oil. For most satisfactory engine life, fuels containing less than
0.5% sulfur should be used.
Fuel oil should be clean and free of contamination. Storage tanks should be inspected regularly for dirt, water,
or water-emulsion sludge, and cleaned if contaminated. Storage instability of the fuel can lead to the formation
of varnish or sludge in the tank. The presence of these contaminants for storage instability must be resolved
with the fuel supplier.
DETROIT DIESEL FUEL OIL SPECIFICATIONS
Detroit Diesel Allison designs, develops, and manufactures commercial diesel engines to operate on diesel
fuels classified by the ASTM as Designation D-975 (grades 1-D and 2-D). These grades are very similar to
grades DF-1 and DF-2 of Federal Specification VV-F-800. Residual fuels and furnace oils, generally, are not
considered satisfactory for Detroit Diesel engines. In some regions, however, fuel suppliers may distribute one
fuel that is marketed as either diesel fuel (ASTM D-975) or domestic heating fuel (ASTM D-396) sometimes
identified as furnace oil. In this case, the fuel should be investigated to determine whether the properties
conform with those shown in the Fuel Oil Selection Chart presented in this specification.
The Fuel Oil Selection Chart also will serve as a guide in the selection of the proper fuel for various
applications. The fuels used must be clean, completely distilled, stable, and noncorrosive. Distillation range,
cetane number, and sulfur content are three of the most important properties of diesel fuels that must be
controlled to insure optimum combustion and minimum wear. Engine speed, load, and ambient temperature
influence the selection of fuels with respect to distillation range and cetane number. The sulfur content of the
fuel must be as low as possible to avoid excessive deposit formation, premature wear, and to minimize the
sulfur dioxide exhausted into the atmosphere.
To assure that the fuel you use meets the required properties, enlist the aid of a reputable fuel oil supplier. The
responsibility for clean fuel lies with the fuel supplier as well as the operator.
During cold weather engine operation, the cloud point (the temperature at which wax crystals begin to form in
diesel fuel) should be 10 (6 ) below the lowest expected fuel temperature to prevent clogging of the fuel
filters by wax crystals.
At temperatures below -20 (-29 ), consult an authorized Detroit Diesel Allison service outlet, since particular
attention must be given to the cooling system, lubricating system, fuel system, electrical system, and cold
weather starting aid for efficient engine starting and operation.
When prolonged idling periods or cold weather conditions below 32 (0 ) are
encountered, the use of lighter distillate fuels may be more practical. The same
consideration must be made when operating at altitudes above 5000 feet.
DIESEL LUBRICATING OILS
All diesel engines require heavy-duty lubricating oils. Basic requirements of such oils are lubricating quality,
Lubricating Quality: The reduction of friction and wear by maintaining an oil