The energy released during combustion of hydrocarbon fuel increases as the molecule chain length decreases, so gasoline fuels with higher ratios of the shorter chain alkanes such as heptane, hexane, pentane, etc. can be used under certain load conditions and combustion chamber geometries to increase engine output which can lead to lower fuel consumption, although these fuels will be more susceptible to predetonation ping in high compression ratio engines. Gasoline direct injection compression ignition engines make more efficient use of the higher combustion energy short chain hydrocarbons as the fuel is injected directly into the combustion chamber during high compression which auto-ignites the fuel, minimizing the amount of time that the fuel is available in the combustion chamber for predetonation.
The energy released during combustion of hydrocarbon fuel increases as the molecule chain length decreases, so gasoline fuels with higher ratios of shorter-chain alkanes such as heptane, hexane, and pentane can be utilized under specific load conditions and combustion chamber configurations to boost engine output, which can result in reduced fuel consumption. Nevertheless, these fuels are more prone to predetonation pinging in high-compression ratio engines.