Forty miles in a prototype is enough to demonstrate that Bentleyâ€™s first ever diesel is going to be a work of art
This is a Bentley with a diesel engine. And that was the first time you will ever have read those words.
Until now, Bentley has never made an oil-burner. But hereâ€™s a Bentayga with the VW Groupâ€™s 4.0 V8 TDI, as found in the Audi SQ7, which produces 429bhp and 664lb ft. Thatâ€™s the same output as the W12 already found in the Bentayga â€“ but with top torque on stream from trifling 1000rpm.
What weâ€™re looking at here is a prototype, but one with the refinement of a showroom car. Its engine is the same deep down as the SQ7â€™s, meaning itâ€™s boosted by a supercharger and two turbos, but Bentley has tuned it to deliver its power with a smooth surge rather than a monstrous thump in the back.
The companyâ€™s engineers have also managed to make it almost silent and free of vibration, whether at tickover or under any sort of driving conditions you can think of. It might as well be a petrol engine â€“ the only real difference is at the sort of speeds that lose you your licence in the UK, where the W12 keeps on pulling hard once the dieselâ€™s race is run.
Our brief stint behind the wheel of this prototype lasted all of forty miles, and most of them were spent accelerating as hard as possible at every opportunity in a bid to find any chinks in the TDIâ€™s armour of refinement (we failed). The result was 25.7mpg on the trip computer, which isnâ€™t the 35.8mpg Bentley claims but might be under normal conditions. With what Bentley calls â€˜state of the artâ€™ emissions management, too, the Bentayga Diesel complies with all current and known future regs.
If you like the sound of all this, and you anticipate having Â£135,800 left in your bank account after Christmas, thatâ€™s when the Bentayga Diesel will go on sale. A W12 would cost you almost Â£25k more, so thatâ€™s a useful saving â€“ which will, of course, land straight in the options list and disappear with a loud plop.