Operation and maintenance manual

QSB4.5 and QSB6.7 Fuel Recommendations and Specifications
Section V - Maintenance Specifications Page V-9
Fuel Recommendations and Specifications
Fuel Recommendations
WARNING
Do not mix gasoline, alcohol, or gasohol with diesel fuel. This mixture can cause an explosion.
CAUTION
Due to the precise tolerances of diesel injection systems, it is extremely important that the fuel be kept clean
and free of dirt or water. Dirt or water in the system can cause severe damage to both the fuel pump and the
fuel injectors.
CAUTION
Lighter fuels can reduce fuel economy or possibly damage fuel system components.
Cummins Inc. recommends the use of ASTM number 2D fuel. The use of number 2D diesel fuel will result in optimum
engine performance.
At operating temperatures below 0°C [32°F], acceptable performance can be obtained by using blends of number 2D
and number 1D.
The following chart lists acceptable substitute fuels for this engine.
Acceptable Substitute Fuels
Number
1D
Diesel
(1)
(2) (3)
Number
2D
Diesel
(3)
Number
1K
Kerosene
Jet-A Jet-A1 JP-5 JP-8 Jet-B JP-4 CITE
A OK Not OK A A A A Not OK Not OK Not OK
An "A" means OK only if fuel lubricity is adequate. This means the BOCLE number is 3100 or greater as measured
by ASTM specification D6078, Scuffing Load Ball On Cylinder Evaluator (SLBOCLE). Lubricity can also be
measured by ASTM, specification D6079, ISO 12156, High Frequency Reciprocating Rig (HFRR) in which the fuel
must have a wear scar diameter of 0.45 mm [0.02 in] or less.
Any adjustment to compensate for reduced performance with a fuel system using alternate fuel is not warrantable.
Winter blend fuels, such as found at commercial fuel-dispensing outlets, are combinations of number 1D and 2D
diesel fuels and are acceptable.
NOTE: Cummins Inc. recommends that the cetane number of diesel fuel be a minimum of 45 for engines that are
expected to operate at temperatures below 0°C [32°F] and a minimum of 40 for engines that are operated at
temperatures above 0°C [32°F].
NOTE: Using diesel fuel with lower than recommended cetane number can cause hard starting, instability, and
excessive white smoke. To maintain satisfactory operation at low ambient temperatures, it is important to specify
diesel fuel of the correct cetane number.
Additional information for fuel recommendations and specifications can be found in Fuel for Cummins® Engines,
Bulletin 3379001. See ordering information in the back of this manual.