Munich's first 'M Performance' version of its X4 crossover basically reconfigures the X4 xDrive35i's engine and chassis to give it more speed and improved driving dynamics, while barely touching the cosmetics.
The only telltale signs over a regular X4 with an M Sport package are the Ferric Gray metallic accents on the front bumper and mirror caps, the 19-inch alloys, separated twin exhausts with black chrome tailpipes, a 3-Series-sourced M sport steering wheel, model-specific door sills and “X4 M40i” digital lettering on the instrument cluster.
At the heart of the M40i lies an improved iteration of the xDrive35i's 3.0-liter turbocharged-six delivering 355hp (360PS) between 5,800 and 6,000 rpm and 343 lb-ft (465Nm) of peak torque, an increase of 54hp (54PS) and (65Nm) over the X4 xDrive35i.
Among other upgrades made to the 3.0L mill is a new forged steel crankshaft, pistons with a modified top ring, different crankshaft bearings, high performance spark plugs, a higher level of turbo boost pressure and an increase in the amount of fuel injected, separate oil cooler, an "aerodynamically tuned air intake manifold" and a new exhaust system.
What's interesting about this unit is its codename "N55B30T0" with the last letter "T" referring to "Top" power output class, according to BMW's engine nomenclature. Various sources have used the same code for the upcoming M2's engine in the past, so if true, it could deliver the same output as in the X4.