Bentley’s dozen – Part two

The Continental GT has always been rumoured to be a 200mph car although we officially only claimed 198mph. The Flying Spur as the longer car was aerodynamically slightly more efficient and even at Nardo we usually achieved 200mph+. A certain Andrew Frankel – then of Autocar – suggested we put this to the public test, so we met at Nardo and in spite of its curvature and usually unfavourable winds, he broke the 200mph barrier.

When the wind was blowing behind the car the GPS readout showed it doing 208mph, and the only reason it didn’t go even faster was that was the speed at which it hit the rev-limiter in top gear. We tried setting the cruise control for 207mph but, spoilsports that they were, Bentley had decided that 186mph (300km/h) was more than fast enough for this particular function and had set the upper parameter there – AF.

It was obvious from the W12’s performance in the hands of the customers and, of course, our own, that the engine had a lot more potential. So Brian Gush’s Powertrain team started a development programme also drawing on lessons learned from the Nardo 24-hour speed record engine. Working mainly on reducing friction and internal pumping losses, the power increased from 552bhp to 601bhp for the new Speed version; torque from 479lb ft to 553lb ft constant from 1800 to 5600rpm, this partly limited by the strength of the gearbox. The same modifications flowed into the mechanically identical 552bhp ‘standard’ version which then had to be de-tuned to keep it down to that power.

Fuel consumption was usefully reduced by about eight per cent with that step. It may not be much of a factor in the buying decision for a £150,000 car, but our customers are often very car-minded, plus fuel range is a consideration and many customers noticed that their new GT Speed used less fuel than the previous GT.

When the certification testing of the new engine was completed someone sent a chart of power, torque and efficiency (as brake-specific fuel consumption or BSFC) to Ferdinand Piëch, now Group Chairman, who always had a keen (and benevolent) eye on Bentley. To our great surprise we received that chart back from him with ‘Sehr gut!’ hand-written on it and signed – rare praise from the master.

By then the Continental family was by far the best-selling 12-cylinder car range in the world with around 9000 per year, well ahead of the V12s from Ferrari, BMW or Mercedes, let alone Aston Martin or Lamborghini, many of them more associated with 12-cylinders before that, when Bentley was mainly associated with our iconic pushrod V8.

After the very successful first- and second-generation Continentals GT, GTC and Flying Spur, a major change to the engine came for the third-generation model. With the change-over to the VW Group’s MSB platform, co-developed between Bentley and Porsche, the engine was moved backwards in the chassis over the front axle and the drive taken through the crankcase. At the same time dual (port plus direct) injection was introduced on the engine combined with a new dual-clutch transmission. All this required a major redesign, leading to a further increase in power and reduction in fuel consumption and all emissions.

With CO₂ requirements becoming ever more stringent across the world, the era of 12-cylinder engines is drawing to a close. This process has been further facilitated by extremely successful downsizing while increasing power and torque, so that displacements of more than four litres are no longer required to deliver any level of performance one may sensibly use on the road, especially when boosted by a performance-oriented hybrid system.

Moreover, electric luxury and sporty cars may still be lacking in emotion for many drivers, but they clearly eliminate many of the development issues that we have traditionally had to solve: pick-up, noise, harsh shifts, vibrations etc. Meanwhile they offer dragster-style acceleration from rest of a kind a 12-cylinder engine had always been best at providing in the past. So there will be no shortage of performance or refinement with hybridised V8s or V6s and EVs, maybe only on emotion and the magic of that number ‘12’.

When the W12 is retired after 21 years in production, more than 100,000 examples will have been built, the vast majority in Crewe. This makes it the most successful 12-cylinder engine of the 21st century. In fact, only Jaguar’s V12, with around 162,000 produced according to the Jaguar Daimler Heritage Trust, was built in greater numbers. And only one other 12-cylinder engine of any kind, automotive or otherwise, surpasses the W12. Close to 150,000 Rolls-Royce Merlin aero engines were made out of wartime necessity in factories in America and Britain, one of those, of course, being in Crewe. The very factory where the W12 was built, no less, which surely makes Pyms Lane the 12-cylinder capital of the world.

At Bentley the W12 bows out with a final series and some special cars giving a glimpse to future models: the Bacalar and Batur, the latter with 740bhp.

Next month, the last W12 will be manufactured at its Crewe home. Rather fittingly, it’s not destined for a car – instead, it will be retained by Bentley and put on permanent display, alongside an original Merlin V12 from the factory’s early days. The perfect bookends of engine production in Crewe.

And in case you still want a new W12 Bentley: sorry – they all sold out long ago.

Once more, great thanks to all the Powertrain colleagues at Bentley Motors and the Volkswagen Group for their dedication, effort and achievements that made this great engine possible – Uli