The Civic Si engine is a dual overhead cam (DOHC) all-aluminum, 2.0-liter inline four-cylinder design that uses 16 valves, a high-performance version of the i-VTEC system and a specially tuned high-volume intake manifold. The Civic Si produces 197 horsepower at 7800 rpm, up from 160 horsepower at 6500 rpm and torque increases from 132 lb-ft. at 5000 rpm to 139 lb-ft. at 6200 rpm. At nearly 100 horsepower per liter, it has one of the highest specific outputs of any production engine in the world.

In keeping with Honda's proven commitment to the environment, the Civic Si engine meets strict Low Emission Vehicle-2 (LEV-2) tailpipe emissions standards. Engine, fuel tank and catalytic converter modifications made for 2006 have lowered evaporative emissions by 75 percent to achieve a LEV-2 Evaporative Emissions rating.

The Civic Si is available exclusively with a short-throw 6-speed manual transmission. The final gear ratio is a low 4.765:1 that complements the additional horsepower and provides enhanced acceleration. Designed to be compact and lightweight, the 6-speed has also been engineered to provide the lightning-quick shift action of a racecar transmission. Synchronizers (triple cone on gears 1 and 2, double cone on gears 3 and 4, and single cone carbon on gears 5 and 6) help reduce shifting load for a light, responsive feel. The Si also includes a short-throw clutch with a torsion mechanism that enhances clutch refinement in terms of engagement and feel.

Civic Si Powertrain At-A-Glance
Engine