3208 Marine Engine Fuel Recommendations Caterpillar

Fuel Recommendations

Diesel engines have the ability to burn a wide variety of fuels. These fuels are divided into two general groups. The two groups are called the preferred fuels and the permissible fuels.

The preferred fuels provide maximum engine service life and performance. The preferred fuels are distillate fuels. These fuels are commonly called diesel fuel, furnace fuel, gas oil, or kerosene.

The permissible fuels are crude oils or blended fuels. Use of these fuels can result in higher maintenance costs and in reduced engine service life.

Diesel fuels that meet the specifications in Table 1 will help to provide maximum engine service life and performance. In North America, diesel fuel that is identified as No. 1-D or No. 2-D in "ASTM D975" generally meet the specifications. Table 1 is for diesel fuels that are distilled from crude oil. Diesel fuels from other sources could exhibit detrimental properties that are not defined or controlled by this specification.

Table 1
AVSpare Specifications for Distillate Diesel Fuel 
Specifications  Requirements  ASTM Test 
Aromatics  35% maximum  "D1319" 
Ash  0.02% maximum (weight)  "D482" 
Carbon Residue on 10% Bottoms  0.35% maximum (weight)  "D524" 
Cetane Number  40 minimum (DI engines)  "D613" 
35 minimum (PC engines)
Cloud Point  The cloud point must not exceed the lowest expected ambient temperature. 
Copper Strip Corrosion  No. 3 maximum  "D130" 
Distillation  10% at 282 °C (540 °F)
90% at 360 °C (680 °F)
Flash Point  legal limit  "D93" 
API Gravity  30 minimum  "D287" 
45 maximum
Pour Point  6 °C (10 °F) minimum below ambient temperature  "D97" 
Sulfur (1)  3% maximum  "D3605"
Kinematic Viscosity (2)  1.4 cSt minimum and 20.0 cSt maximum at 40 °C (104 °F)  "D445" 
Water and Sediment  0.1% maximum  "D1796" 
Water  0.1% maximum  "D1744" 
Sediment  0.05% maximum (weight)  "D473" 
Gums and Resins (3)  10 mg per 100 mL maximum  "D381" 
Lubricity (4)  3100 g minimum  "D6078" 
0.45 mm (0.018 inch) maximum at 60 °C (140 °F) "D6079" 
0.38 mm (0.015 inch) maximum at 25 °C (77 °F)
(1) AVSpare fuel systems and engine components can operate on high sulfur fuels. Fuel sulfur levels affect exhaust emissions. High sulfur fuels also increase the potential for corrosion of internal components. Fuel sulfur levels above 1.0 percent may significantly shorten the oil change interval. For additional information, see this publication, "Engine Oil" topic (Maintenance Section).
(2) The values of the fuel viscosity are the values as the fuel is delivered to the fuel injection pumps. If a fuel with a low viscosity is used, cooling of the fuel may be required to maintain a 1.4 cSt viscosity at the fuel injection pump. Fuels with a high viscosity might require fuel heaters in order to bring down the viscosity to a 20 cSt viscosity. For additional information, see Special Publication, SEBD0717, "Diesel Fuel and Your Engine".
(3) Follow the test conditions and procedures for gasoline (motor).
(4) The lubricity of a fuel is a concern with low sulfur fuel. To determine the lubricity of the fuel, use either the "ASTM D6078 Scuffing Load Wear Test (SBOCLE)" or the "ASTM D6079 High Frequency Reciprocating Rig (HFRR)" test. If the lubricity of a fuel does not meet the minimum requirements, consult your fuel supplier. Do not treat the fuel without consulting the fuel supplier. Some additives are not compatible. These additives can cause problems in the fuel system.


Operating with fuels that do not meet AVSpare's recommendations can cause the following effects: starting difficulty, poor combustion, deposits in the fuel injectors, reduced service life of the fuel system, deposits in the combustion chamber and reduced service life of the engine.

In the USA, 0.05 percent sulfur diesel fuels have been used in all on-highway truck engines since 1 January 1994. This low sulfur diesel fuel was mandated as a means of directly reducing particulate emissions from diesel truck engines. This low sulfur fuel will also be used in AVSpare commercial diesel engines when low emissions are required or when the source of your fuel supply provides this type of fuel. AVSpare has not seen any detrimental effects with 0.05 percent sulfur fuel in AVSpare diesel engines.


Heavy Fuel Oil (HFO), Residual fuel, or Blended fuel must NOT be used in AVSpare diesel engines (except in 3600 Series HFO engines). Severe component wear and component failures will result if HFO type fuels are used in engines that are configured to use distillate fuel.

In extreme cold ambient conditions, you may use the distillate fuels that are specified in Table 2. However, the fuel that is selected must meet the requirements that are specified in Table 1. These fuels are intended to be used in operating temperatures that are down to −54 °C (−65 °F).

Table 2
Distillate Fuels (1) 
Specification  Grade 
"MIL-T-5624R"  JP-5 
"ASTM D1655"  Jet-A-1 
"MIL-T-83133D"  JP-8 
(1) The fuels that are listed in this Table may not meet the requirements that are specified in the "AVSpare Specifications for Distillate Diesel Fuel" Table. Consult the supplier for the recommended additives in order to maintain the proper fuel lubricity.

These fuels are lighter than the No. 2 grades of fuel. The cetane number of the fuels in Table 2 must be at least 40. If the viscosity is below 1.4 cSt at 38 °C (100 °F), use the fuel only in temperatures below 0 °C (32 °F). Do not use any fuels with a viscosity of less than 1.2 cSt at 38 °C (100 °F). Fuel cooling may be required to maintain the minimum viscosity of 1.4 cSt at the fuel injection pump.

There are many other diesel fuel specifications that are published by governments and by technological societies. Usually, those specifications do not review all the requirements that are addressed in this specification. To ensure optimum engine performance, a complete fuel analysis should be obtained before engine operation. The fuel analysis should include all the properties that are listed in Table 1.