Diesel fuel in general is any liquid fuel used in diesel engines, whose fuel ignition takes place, without spark, as a result of compression of the inlet air mixture and then injection of fuel. (Glow plugs, grid heaters and heater blocks help achieve high temperatures for combustion during engine start-up in cold weather. Diesel engines have found broad use as a result of higher thermodynamic and thus fuel efficiencies. This is particularly noted where diesel engines are run at part-load; as their air supply is not throttled as in a petrol engine, their efficiency still remains very high.

The most common type of diesel fuel is a specific fractional distillate of petroleum fuel oil, but alternatives that are not derived from petroleum, such as biodiesel, biomass to liquid (BTL) or gas to liquid (GTL) diesel, are increasingly being developed and adopted. To distinguish these types, petroleum-derived diesel is increasingly called Petro Diesel. Ultra-low-sulphurdiesel (ULSD) is a standard for defining diesel fuel with substantially lowered sulphur contents.

Property Unit Limits Method
Density @ 15°C kg/l max. 0.87 D4052/ D1298
Colour ASTM max. 2.5 D 1500
Cetana Index or D 976
Cetana Number min. 49 D 613/ D6890
Viscosity @ 40°C mm2/s 1.5-5.8 D 445
Cloud Point °C max. 18 D 2500
Sulphur mg/kg max. 500 D2622/ D4294
Copper Corrosion (3hr/50°C) max. 1 D130
Water by distillation % v max 0.05 D95
Flash Point °C min. 60 D 93
Distillation – 50% Recovery °C Report
Distillation – 90% Recovery °C D86
Distillation – 95% Recovery °C 370 max D 86
Appearance Bright & Clear at ambient D 482
Ash % wt max. 0.01 D482/ D189
Carbon Residue Conradson (on 10% distillation residue) % wt 0.2 max D189/ D4530/ D 613
Pour Point °C max. 15 D 97
Sediment % wt max. 0.01 D 473
Strong Acid Number mgKOH/g Nil D 974
Total Acid Number mgKOH/g max. 0.25 D664/ D 974
Electrical Conductivity, pS/m pS/m min. 50 D2624
Lubricity, microns microns D6079


Test Unit Method Min
Density @ 15°C Kg/L ASTM D 4052 – 96 815
Kg/L ASTM D 1298 – 99
Color None ASTM D1500 Bright & Clear
Distillation T 90 % °C ASTM D 86 – 00a
Kinematic Viscosity @ 40°C Mm2/S ASTM D 445 – 97 2.0
Sulphur Content wt% m/m ASTM D 2622 – 98
Carbon Residue % mm ASTM D 4530 – 93
Flash Point °C ASTM D 93 – 00c
Total Acid Number mgKOH/g ASTM D 974 – 97 0.1 (Typical)
Strong Acid Number mgKOH/g ASTM D 974 – 97 Nil (Typical)
Biological Growth
Water Content Mg/kg ASTM D1744-92
FAME Content wt%
Ash wt% ASTM D 482 – 00a 0.002 (Typical)
Methonal & Ethanol Content ASTM D4815
Cetane Index ASTM D 4737-96a 45
Cetane Number ASTM D 613-95 48
Pour Point °C ASTM D 97 – 96a
Total Acid Number Mg KOH/g ASTM
Sediment Content % m/m ASTM D 473 – 95
Copper Strip Corrosion ASTM D 130 – 94