The ________ indicates the amount of energy in the fuel used by the engine.

The ________ indicates the amount of energy in the fuel used by the engine.

• A. Brake efficiency
• B. Fuel energy density
• C. Thermal efficiency
• D. Compression ratio

Answer: (C)

Energy density is the term that tells you how much energy is stored in the fuel itself, per unit mass or volume. It’s the fuel’s energy content that is available to be released during combustion. This is different from how efficiently that energy is converted into useful work, which is described by thermal efficiency. So the amount of energy in the fuel used by the engine is indicated by the fuel’s energy density. The other concepts relate to how effectively that energy is turned into work or to engine design (which affects performance), not to how much energy the fuel contains in the first place.

Energy density is the term that tells you how much energy is stored in the fuel itself, per unit mass or volume. It’s the fuel’s energy content that is available to be released during combustion. This is different from how efficiently that energy is converted into useful work, which is described by thermal efficiency. So the amount of energy in the fuel used by the engine is indicated by the fuel’s energy density. The other concepts relate to how effectively that energy is turned into work or to engine design (which affects performance), not to how much energy the fuel contains in the first place.