The 2.4-tonne, 4.9-metre-long X5 M splits the difference between the two, making it the fastest-accelerating SUV we’ve tested.
Fabulous traction and a brilliant launch control system combine for a ferocious standing start. The BMW needs one more gearchange than the Range Rover Sport SVR to hit 60mph, yet it still beats its rival over the benchmark sprint by a clear two-tenths of a second.
And yet only when third gear is selected does the X5 M feel as if it hits a blazing full stride. By the time 100mph comes around, the Range Rover Sport SVR is trailing half a second behind and steadily retreating in the rear-view mirror. And even here – despite the sheer quantity of air through which the X5 is cleaving – neither the M4 nor the M5 is more than a second ahead.
The X5 M’s engine and gearbox are little short of sensational. Throttle response manages to feel at once perfectly clean, wonderfully savage and progressive and linear. Torque builds quickly enough below 3000rpm to make the car fast no matter how many times you’re inclined to downshift.
And the icing on the cake is a delicious crescendo to the power delivery between 6000 and 7000rpm. It’s the last thing you’re expecting – either of a turbocharged engine or from an SUV.
Below those sorts of crank speeds, the V8 could do with a little more rasp. It’s smooth and entirely pleasant to listen to, but the engine lacks the stirring aural virtuosity and charisma that its performance merits.
The gearbox, meanwhile, is much better at full-bore upshifts than simple fuss-free manoeuvring. The car declines to creep at first when you ease off the brake pedal, and while it can be persuaded to eventually by a singular prod of the accelerator, it isn’t as easy to park or turn around as a big luxury car ought to be.
Braking performance is, however, every bit as good as the acceleration. The car hauls up from 70mph very powerfully indeed, with good pedal feel and without excessive fade – which is particularly reassuring to report from such a big BMW M car.