Though the Accord four-cylinder engines and the V-6 with automatic transmission are all called i-VTEC powerplants, it is important to note that the details in each application differ. Honda's four-cylinder engines have double overhead camshafts (DOHC) and i-VTEC that is comprised of VTEC + Variable Timing Control (VTC) of the intake camshaft for optimized power production and fuel efficiency. In addition, PZEV variants also idle one of the two exhaust valves in each cylinder at low rpm for enhanced emissions performance. Accord V-6 engines (with the automatic transmission) use a Single Overhead Camshaft (SOHC) design that features i-VTEC with Variable Cylinder Management (VCM) to maximize fuel economy.
