The heating value or heat of combustion is a measure of the energy available from the fuel. The fraction or percentage of the heat of combustion that is converted to useful work is a measure of the thermal efficiency of an engine. Thus, a knowledge of the heat of combustion of the fuel is basic to the engineering of automotive engines. This SAE Information Report provides information on the standardized procedures for determining the heat of combustion of fuels that may be used for automotive engines. The changes to SAE J1498 include: SAE Publications - Added SAE Paper 2010-01-1517 Other Publications and Sections 5, 9, and 10 - Updated ASTM alphanumeric designations and titles. Section 10 - Added discussion of a method to calculate net heating value for gasoline-ethanol blends using ASTM D3338.
The heating value of fuel is a measure of its heat of combustion or energy content as determined under specific conditions. Higher (gross) and lower (net) heating values are discussed. Gross (liquid water) and net (gaseous water) heating values differ by the heat of vaporization of the water in the combustion product mixture. This SAE Recommended Practice discusses the measurement and calculated estimated heating values for gaseous, liquid, and solid fuels.