As with all other M40-badged BMW models, the engine is a real peach. Despite being able to fire the X3 M40D from 0-62 mph in 4.9 sec, if you’ve got Comfort or Eco Pro mode selected, the six-cylinder unit is hushed and sends few tremors through the controls. While the eight-speed automatic gearbox is keen to smoothly shuffle into the highest ratio possible, it’s just as quick to change down should you require a slice of acceleration. Not that a downshift is always necessary; there’s ample shove from low in the rev range. Cycle through to Sport or Sport Plus mode and the motor’s character changes significantly. With the gearbox holding onto ratios for longer and thumping them through far more quickly, the engine really comes alive, howling its way to the redline with pops and cracks to accompany gear changes and bouts of deceleration. Put simply, it’s far more characterful than the SQ5’s V6.