Based on a new generation of large-displacement four-cylinder engines that was designed for greater efficiency, GM proprietary Computational Fluid Dynamics (CFD) analysis techniques were used to develop an all-new combustion system with a higher compression ratio.

The new combustion system features improved knock resistance and higher-flowing intake and exhaust ports in the cylinder head. The 2.5L also features a high-pressure direct-injection fuel system, dual overhead camshafts with continuously Variable Valve Timing, electronic throttle control, and pistons with jet-spray oil cooling. All features coalesce to enhance efficiency, performance, emissions, and drivability.