0D-1D engine modeling Biodiesel Ion current Technology: general issues alternative fuels artificial neural network axial engines biofuels burning velocity calorimeter combustion bomb combustion optimization cooperative combustion diagnosis and control cycle-to-cycle variation cylinder pressure cylinder-to-cylinder variation diesel engines diethyl ether downsizing downspeeding emissions ethanol exhaust emissions and spark-ignition engine experiments field-programmable gate array fuel consumption fuel economy fuels internal combustion engine iso-octane