The shape-shifting engine
Compression ratio—how hard the pistons squeeze the mix of air and fuel in your cylinders—is one of an engine's defining characteristics. High compression delivers that kick off the line or the ability to pull a heavy load from a standstill. But you don't always need that much power. Gearheads have dreamed of tweaking compression since internal combustion first roared to life, and Infiniti's engineers have spent two decades on the problem. They finally nailed it. Their solution: Adjust the reach of the pistons within the cylinders via linkages on the connecting rods and crankshafts that drive the pistons up and down. When the car's computer calls for performance, the pistons travel farther up the cylinders and create higher compression. If the system doesn't need the extra oomph, it holds the pistons back, saving fuel. The result: compression ratios that can nearly double when you need extra power, generating up 268 horsepower and 288 pound-feet of torque.

Eric Hagerman