Honda R Engine

The Honda R engine is an inline-four engine launched in 2006 for the Honda Civic (Non-Si). It is fuel injected, has an aluminum-alloy cylinder block and cylinder head, is a SOHC 16-valve design (four valves per cylinder) and utilizes Honda's i-VTEC system. The R series engine has a compression ratio of 10.5:1, features a "drive by wire" throttle system which is computer controlled to reduce pumping losses and create a smooth torque curve. The engine uses many technologies to improve economy. Piston rings are given an ion plating, weight is reduced with plastic and aluminum parts and variable length intake manifolds that maintain ram air at a wide rpm range. The automatic transmission model is rated at California Air Resources Board (CARB) ULEV-2 (Ultra Low Emissions Vehicle) with fuel economy 25 mpg (9.4 L/100 km; 30 mpg) city, and 36 mpg (6.5 L/100 km; 43 mpg) highway. It also uses the same computer (engine control unit) controlled distributorless coil-on-plug ignition as the Honda K-series engines.