BMW increasing the power output of the straight-six diesel in the X7 (badged xDrive40d) from 335bhp to 347bhp might sound about as necessary as nicking your friend’s last chip when you’ve just ordered a super-size Mac Whopper meal.
However, the point was not making this humongous SUV a microsecond faster to 62mph but reducing its consumption, that extra 12bhp coming from a new mild-hybrid system – a crankshaft-mounted starter-generator on the eight-speed automatic gearbox, with a small battery to hold its charge.
This comes as part of the mid-life facelift for the largest BMW – or rather, what was the largest BMW until the arrival of the XM. Compared with that overwrought monster, this seven-seater, which focuses much more on refined luxury than aggressive sportiness, looks almost shy and retiring.
That’s despite it having something of a killer-robot stare, the result of the front light clusters being split as part of a fairly significant redesign. So yes, the most notable element of a BMW design is not, for once, on grilles that make a commercial wok look small – albeit maybe only because the X7 has had those since day one…
As ever, the effect of this is a matter of personal opinion, but there’s no denying that it matches the visual attitude of the M Sport specification that most will order (the alternative is the Excellence, which thankfully isn’t inappropriately named).
Diesel and performance don’t automatically go together in many minds, but my goodness, the X7 xDrive40d pulls like Casanova. Call for it all on a motorway slip road and a relentless flow of torque takes you to 62mph in 5.9sec. In a seven-seat, 5.2-metre-long, 2490kg brick. Thank you very much, 516lb ft of torque – more than in a Ferrari Enzo – from a lowly 1750rpm.
Even more powerful engines are available in the X7: the ‘B58’ turbo petrol straight six, with 375bhp, up 50bhp thanks to the same 48V measure, badged xDrive40i; and a 4.4-litre twin-turbo petrol V8, still with 523bhp but in new MHEV form now called the M60i (not M50i) xDrive. Surely nobody could truly need more power than this, though? Furthermore, the petrols will be less economical than this diesel, which itself only reaches the mid-30s in terms of MPG, officially and in practice, even if you don’t hold back.
The ‘B57’ also doesn’t sound like a diesel – no clattering or gravelly loudness – and is smooth as marble in its delivery, meaning the only real argument against is future-proofing, what with ULEZs and more.