The shape of the Alpina XD3 Biturbo may be familiar, but this BMW X3-based model is the first SUV in Alpina’s history. That in itself is significant enough, but the fact that the XD3 is also the fastest-accelerating diesel-engined SUV you can buy makes it something of a landmark vehicle.
The stats are deeply impressive. In Alpina spec, BMW’s already stonking twin-turbo 3.0-litre diesel gets a 36bhp power boost to 345bhp and an extra 52lb ft of torque at 516lb ft, largely thanks to optimised air intake and exhaust flows. That’s enough to propel the 1910kg XD3 from 0-62mph in an eye-watering 4.9sec – a level of acceleration that you’d need a Porsche Cayenne Turbo to beat.
There’s a small penalty to pay in terms of fuel economy and emissions compared with the standard X3 xDrive35d, but the XD3’s 41.5mpg combined and 180g/km of CO2 remain on a par with the class best, notably the 309bhp bi-turbo Audi SQ5.
The XD3’s performance is every bit as urgent as those figures suggest. Mated to a recalibrated ZF eight-speed automatic transmission, the uprated engine revs relatively enthusiastically for a big diesel and produces an encouragingly throaty growl in the upper half of its rev range, but it’s the relentless torque that dominates the way the XD3 goes down the road. In short, it goes like stink.
As always, it’s the work Alpina has done on the chassis side that is the key difference between one of its products and the BMW equivalent, but in this case the incremental gains seem greater than on recent 3-series or 5-series-based offerings and make the XD3 feel genuinely sporting by SUV standards.