Although many Americans remain unfamiliar with the Alfa Romeo brand, the Giulia Quadrifoglio has the potential to make or break the Italian firm in the U.S.

Appealing to the upper-end of the market and to those customers that generally know their stuff, the high-performance sedan aims to shake up the established German hierarchy and according to some reviews, is the new benchmark.

On paper, Alfa Romeo says that the model’s 2.9-liter twin-turbocharged V6 engine delivers 505hp and 443 lb-ft on the flywheel, identical to the output of the Mercedes-AMG C63 S. However, on a dyno, how does that figure translate to the road?

Well, one U.S. Giulia Quadrifoglio owner recently strapped the car to a dyno where it managed to deliver 392 hp and 389 lb-ft (527 Nm) of torque at the rear wheels. Such a horsepower difference is perhaps slightly more than you would expect with a typical 15 per cent driveline loss but the uploader notes the car was tested on a Mustang AWD dyno, a setup known for delivering lower figures than many other dynos.

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