Just how much energy is contained in a liter of gasoline or gallon of diesel?
Energy contents are expressed as either High (gross) Heating Value (HHV) or Lower (net) Heating Value (LHV). LHV is closest to the actual energy yield in most cases. HHV (including condensation of combustion products) is greater depending mainly on the hydrogen content of the fuel.
The appropriateness of using LHV or HHV when comparing fuels, calculating thermal efficiencies, etc., really depends upon the application. For stationary combustion engines where exhaust gases are cooled before discharging (e.g. power stations), HHV is more appropriate. Where no attempt is made to extract useful work from hot exhaust gases (e.g. motor vehicles), the LHV is more suitable. In practice, many European publications report LHV, whereas North American publications use HHV.
The tools listed on this page are for estimating purposes only. Calculations should be confirmed with your engineering team.