DIESEL FUELS & DIESEL FUEL SYSTEMS

Diesel Fuels & Diesel Fuel SystemsApplication and Installation GuideCommon Diesel FuelDiesel Fuel GradesA variety of fuel oils, also knownas middle distillates, is marketed foruse in diesel engines. Theirproperties and performance dependupon the refining practices employedand the nature of the crude oils fromwhich they are produced. Becauseof constituents in the oil, somecrude oils are naturally suited forrefinement into high-grade fuelswhile others are best used for lowergradefuels. Similarly, high-gradefuels, low-grade fuels and thevarious grades between themprovide choices for the most suitablefuel for any given installation.Note: The use of very high-grade orvery low-grade fuel oils oftenrequires modification to the fuelsystem and special consideration ofadditional costs that may beencountered. Contact yourCaterpillar dealer for informationregarding the use of these fueltypes.Low GradeLow-grade fuels produce a higherheat value which translates intomore engine power, but they alsoproduce more contaminates thatcould negatively impact engine-life.Additionally, the use of low-gradefuel oil in diesel engines oftenproduces darker exhaust and a morepronounced odor. These attributesmay be objectionable in hospital,office, commercial or urban settingsand require the use of a higher-gradefuel.Page 2The high sulfur content oftenfound in low-grade fuels causescorrosion, wear and deposits in theengine. Fuels that are not volatileenough or don’t ignite rapidly mayleave harmful deposits in the engineand may cause poor starting orrunning under adverse operatingconditions. The use of low-gradefuels may require the use of highpriced, higher detergent lubricatingoils and more frequent oil changes toyield appropriate performance andengine life.High GradeHigh-grade fuels burn cleaner, buthave a lower heat value, whichyields slightly less power. Aviationjet fuels and kerosene are consideredhigh-grade fuels and seldomcontribute to the formation ofharmful engine deposits andcorrosion. Other attributes of highgradefuels include the benefits offaster engine starting and lessfrequent overhauls, and thedrawback of reduced lubricity.American Society for Testing andMaterials (ASTM)Due to the different engineapplications, designs and sizes,standards for the limits of fuelproperties have been set by theAmerican Society for Testing andMaterials (ASTM). Utilizing thecorrect fuel for the engine willminimize wear of the injectionsystem, allowing easier starting andimprove component service life.Experience has proven thatdistillate fuels meeting basic©2005 Caterpillar®All rights reserved.