Adding a bit more efficiency to its base engine, the 2.4-liter Ecotec 4-cylindrer in the 2014 Chevrolet Impala will benefit from the first use of GM's new Intake Valve Lift Control (IVLC) technology. This dual-mode (low-lift/high-lift) system helps reduce pumping losses by matching the amount of air entering the cylinders to the engine's specific real-time load requirements and fully integrates with the Ecotec's existing variable valve timing and duration functions.
Key to the Ecotec's new IVLC optimization system is an innovative rocker arm that can switch between the low- and high-lift intake cam profiles. The mechanism is controlled by the engine computer that constantly monitors both rpm and loads. The IVLC hardware uses oil pressure controlled by a is valve linked to a dual-feed stationary hydraulic lash adjuster to actuate the system. GM says this represents the initial use of this kind of low-friction roller-type finger-follower valvetrain design in a gasoline engine.
"Intake Valve Lift Control works so seamlessly drivers aren't likely to notice it at all," said Mike Anderson, GM global chief engineer for Ecotec engines. "What they will notice is a fuel savings of up to one mile per gallon." While not ready to confirm other future IVLC applications at this time, expect to see it spread to other vehicles equipped with the 2.4-liter Ecotec in fairly short order following the 2014 Impala rollout.