What kind of engine does the BMW M3 have, and what is its horsepower and torque output?

The BMW M3 is powered by a twin-turbocharged 3.0-liter inline-six engine that produces 473 horsepower and 406 lb-ft of torque in the standard model. The M3 Competition model features a more powerful version of the same engine that produces 503 horsepower and 479 lb-ft of torque. The engine is mated to an eight-speed automatic transmission.