Much of this performance is due to the double wishbone rear suspension that goes unchanged from the standard 3-Series. However, its front suspension had to make room for a front axle differential and individual equal length drive shafts. One of these shafts actually runs through the oil pan to keep the engine at a low center of gravity. This is important for balance, as the Xi's body has been raised by 17mm to reduce the risk of sustaining undercarriage damage while off the beaten path. The result is absolutely no torque-steer and only marginal weight added to its steering dynamics.
The extra 90 kg from the AWD system, coupled with the reduction in power caused from friction in the extended driveline, are compensated for by the Xi's increased traction and shorter final drive ratio, when compared to its rear drive siblings. Fortunately it needs only 0.1 second more to shoot from 0 to 100 km/h. Top speed remains the same - electronically limited to 206 km/h. Also, fuel consumption increases only slightly to 8 L/100km.
Fuel economy will likely be the last thing on your mind when you get behind the wheel. With all four wheels harnessed to this wild beast of an engine, the Xi can even tame dirt roads. During one unpaved detour just north of Waterton, Alberta, I was surprised at how tractable it was. The Xi shot forward without hesitation, tracking effortlessly up winding gravel inclines and powering down through low-lying muddy sections. Could a competitive rally version be in its future?
Of course, the 330Xi isn't all about performance. Beautiful wood grain accents and sumptuous leather add warmth to a purposefully understated interior. Workmanship and materials are top quality, with attention to detail apparent at every glance. The 3-Series may be a sport sedan, but you won't be wanting for luxury features.