Also apparently it's going to put out 480 HP (via motortrend) -
http://www.motortrend.com/roadtests/...#ixzz2prLKtozH
The ideal Atkinson cycle captures and compresses an amount of air that, when combusted and expanded throughout the entire power cycle, results in a cylinder pressure that's near atmospheric at the bottom of the piston's stroke, meaning the engine has wrung every bit of energy out of the fuel. Drop the hammer, and those valves shut in time to give you the full 12.3:1 compression (up from 11.8:1) and 5.0 liters of furious power -- 480 horses' worth (up substantially from the IS F's 416). A newly modified version of the current D4S direct-injection with secondary port injection helps make all this work. Torque ratings and further specifications are pending.