The quest for efficient internal combustion has given us turbocharging, port and direct injection, Atkinson-cycle operation, variable valve timing, and individual cylinder ignition timing. Infiniti's VC-Turbo 2.0-liter has all of those, something new: variable compression. Set to debut in 2018 models, the engine uses an articulated multilink system to continuously change the compression ratio, anywhere from 8.0:1 to 14.0:1. The key is a quadrilateral plate  that surrounds—and rotates with—the crankshaft. Attached to this plate are two links. The upper link  joins the piston, like a normal connecting rod; the lower link  runs to a control shaft . A computer-controlled actuator assembly  rotates the shaft, pushing up or tugging down on the lower link. Since upper and lower links are connected to the plate, the lower link shifts the upper link with it. And, as that upper link moves, so does the piston's top-dead-center position, effectively altering compression ratio. Tilting the control shaft in one direction drops top dead center, which lowers the compression ratio, ideal for high boost pressure and better power; the opposite motion raises the compression ratio, delivering maximum efficiency during steady cruising.