This engine, in slightly different states of tune, has gone up against our road test benchmarking gear twice already, in the Audi SQ7 and the Porsche Panamera.

We knew, therefore, how unlikely it would be to let Bentley down, even allowing for the Bentayga’s 2645kg weight and Crewe’s standards on driveability and mechanical isolation.

Matt Saunders Autocar

Matt Saunders

Road test editor
Power-on understeer forces you to deploy engine torque gradually on exit

What we didn’t reckon on were where those standards would take this car above and beyond the refinement we’ve already experienced elsewhere.

The Diesel is astonishingly smooth and quiet. Its V8 declines to send any of the shudders that a compression-ignition engine can transmit into the cabin on start-up, and it settles to a remote, demure idle that isn’t even faintly clattery or brusque.

Frankly, it’s barely audible. The engine raises its voice just loud enough to hear it as you move off but remains pleasant and sweet-sounding as it spins faster, and even at high revs it never intrudes.

Bentley’s W12 is a little more tuneful when worked hard, but the difference between the two engines on tonal richness is remarkably small.

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The W12 does move the Bentayga a bit more forcefully at times, but only when the accelerator is on its stop and the tacho needle is spinning to the redline, which is a mode that you’d expect Bentayga owners rarely to adopt.

To hit a flying 100mph from standing, the Bentayga Diesel needs exactly a second longer than its 12-cylinder rangemate and more than two seconds more than a Range Rover Sport SVR.

But to spirit itself from 40-100mph in sixth, which is a much more telling measure of accessible on-road pace, the Diesel is 1.4sec quicker than the W12 and more than four seconds quicker than the SVR (and with another 60mph still to gain before it needed another gear).

You can imagine how easy that performance would make motorway driving and the towing of heavy trailers, and in what kind of incredibly relaxed style the Bentayga Diesel could pick off slower cars on well-sighted A-roads.

Laid-back, suave, rich and luxurious-feeling pace is absolutely the kind that Bentley’s SUV should provide – and this one has it in glorious abundance.

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