In 2009, BMW unveiled their first M car powered by a turbocharged engine. The twins BMW X5M and X6M launched into the market in a moment less favorable for a vehicle of their caliber, both from a pricing perspective and fuel efficiency.

The M SAV twins came equipped with the latest engine coming from M Division: a V8 4.4 liter twin-scroll engine delivering 555 horsepower at 6,000 rpm and 500 lb-ft of torque from 1,500 to 5,650 rpm. The engine was developed under the internal code S63.

The engine uses the twin-scroll twin turbo technology with High Precision Direct Injection. By positioning the twin-scroll turbochargers together with the catalytic converters in the “V” section between the cylinders, it minimizes the turbo lag and offers better fuel efficiency.

M twin-scroll

A video released by BMW gives us more insight into the production and testing of this new powerplant, so let’s have a look.

Current Spec for X5/6M:
Cylinders/valves 8/4
Capacity in ccm 4395 / Biturbo
Stroke/bore in mm 88.3/89.0
Max. output in kW/bhp at 1/min 408 (555)/6000
Max. torque in Nm at 1/min 680/3400