Fuel conversion efficiency (ηf) of an Internal combustion engine is given by: (Where sfc is specific fuel consumption and QHV is the heating value of fuel)
1
ηf = sfc.QHV
2
\(\rm \eta_f=\frac{sfc}{Q_{HV}}\)
3
\(\rm \eta_f=\frac{1}{sfc.Q_{HV}}\)
4
\(\rm \eta_f=\frac{Q_{HV}}{sfc}\)