Yanking the twin-scroll four-cylinder oil-burner from the heart of a 123d, the Germans put their arts to work and raised output for the D3 to 214hp from the stock 204hp. But like all diesels, the fun lies in the low-end rather than the high-end, and with 450Nm on tap, the fun should be in ample supply. Sprinting from rest to 100km/h in just 6.9s and topping out at 152mph, the D3 combines speed and efficiency. The performance puts the D3 in good standing with the likes of the six-cylinder 325d and 330d - while only burning the fuel required to power four cylinders.
The donor engine gets an impressive 5.2L/100km (45mpg US) in its application in the 123d. While the slightly heavier 3-series chassis and more sport-oriented tuning cut into that number somewhat, it still manages 5.4L/100km (43.5mpg US) and 143g/km CO2. Available in saloon or touring (wagon) form factors, the D3 could be one of the best daily-drivers around.