What does the heat energy or BTU content of a diesel fuel mean?
The energy content of diesel fuel is defined by the amount of energy stored in one gallon. The higher the fuel’s heat of combustion, the more power will be derived from each gallon of fuel consumed. Energy content is measured in British Thermal Units (BTU) per gallon and is related to the fuel’s specific gravity and the temperature range at which it vaporizes. The BTU content per unit volume increases as the specific gravity increases. The BTU content of a unit volume (gallon or liter) of diesel fuel is higher than that of gasoline, and the BTU content of No. 2-D diesel fuel is generally higher than that of No.1-D diesel fuel. The BTU content of No. 2-D diesel fuel is typically about 130,000 BTU/Gal.