the simpliest xplanation for the 2 engines are:4G93 DOHC is like honda civics without VTEC4G92 MIVEC is like honda civics with VTEC just like SiRMIVEC is Mitsubishi Innovative Variable valve Electronic Control equivalent to Honda VTEC Variable Valve timing and lift Electronic Control Equivalent to Nissan VTC Variable Timing Camshaft equivalent to Toyota VVTi Variable Valve Timing inteligent.