The new 2018 Alfa Romeo Stelvio Quadrifoglio Verde is one of the world’s fastest crossovers, boasting a 0-60 mph time of 3.9-seconds and a dizzying top speed of 177 mph – and it’s all thanks to its 505 horsepower Ferrari-derived 2.9-liter twin-turbocharged V6 engine.
The direct-injection all-aluminum engine features a compact, 90-degree design that Alfa says was “was holistically designed for a low center of gravity within the chassis.” Its dual single-scroll turbochargers have also been integrated into the Stelvio’s exhaust manifolds and feature variable boost management for sharper throttle response. No throttle lag here.
The exact displacement of the 2.9-liter engine is 2,891 cc with a single-cylinder displacement of just under half a liter. It features four valves per cylinder, which are actuated through hydraulic lifters. Alfa claims an exact maximum power output of 503 horsepower at 6,500 rpm and 443 lb-ft of torque between 2,500 and 5,000 RPM. Fuel cutoff comes at 7,400 RPM.
Thanks to cylinder deactivation on the engine’s right bank of cylinders, the 2.9-liter engine returns a combined fuel economy rating of 28 MPG US in the Giulia QV. Alfa has yet to announce fuel economy figures for the Stelvio QV, but we’re expecting it to be in the same ballpark. Not that Stelvio QV buyers will be overly concerned with fuel economy.