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VW 6.0L W-12 engine
The Vienna engine symposium used to be one of the better-kept secrets in our business. It’s now in its 36th year, and it is the top event where engineers and executives mingle and discuss current and future topics freely and openly. It’s an event where many conversations are assumed to be off the record—and it’s one of my favorite events in the automotive calendar.
This year, Volkswagen hosted a passel of journalists, so I don’t think I’m breaching etiquette by reporting specifically on what they are sharing at the sprawling Hofburg palace complex—part of which has been a conference center since the 1950s—in the center of Vienna this week.
Ulrich Hackenberg (Audi), Wolfgang Hatz (Porsche), Heinz-Jakob Neußer (VW)
For the VW Group alone, it was worth coming. Audi, Porsche, and Volkswagen’s respective board members for R&D—Ulrich Hackenberg, Wolfgang Hatz, and Heinz-Jakob Neusser [left to right, above]—all showed up. But CEO Martin Winterkorn, who was to speak about “challenges and solutions from a Volkswagen perspective,” pulled out because of the “circumstances,” as the symposium’s leader, Hans-Peter Lenz, put it diplomatically.
The speech he was supposed to deliver was given by Heinz-Jakob Neusser instead, and it included a number of interesting announcements. Lambasted by the former head of the supervisory board, Ferdinand Piëch, for a lack of vision, Winterkorn’s speech draft aimed to prove that VW is well-prepared for the future.
The speech mentioned Tesla’s battery factory in Nevada, Apple’s hiring spree of automotive experts, and a robot car by the Chinese IT company Baidu. “We at Volkswagen are not afraid of these new players in our business,” said Neusser.
That’s great news, and even better news are the powertrains that VW is working on. TDI and TSI engines will remain indispensable for the foreseeable future, Neusser said, “preferably combined with a dual-clutch transmission.”
VW 1.0L 3-cylinder TSI engine
An incredible glimpse into the future comes in the form of a 1.0-liter three-cylinder engine [above] that is fitted with a large single turbo and an electric supercharger for a stunning 272 horsepower and 199 lb-ft of torque.
VW 2.0L Bi-Turbo TDI diesel engine
Neusser also detailed the 2.0-liter four-cylinder TDI [above] that was first announced two years ago. Thanks to an ultra-high-pressure injection system, dual turbocharging with variable turbine geometry, and an electric charger, it makes 300 horsepower and 443 lb-ft of torque. That’s within spitting distance of some V-8 turbo-diesels.
In fact, Neusser is passionate about diesels: “As you all know, this engine [type] has been criticized for allegedly contributing to poor air quality in cities. Frankly, as a sweeping statement, this is rubbish.” And he went on: “Demonizing the diesel engine means working against the goals of climate protection.”
VW 6.0L W-12 engine
Even the monsters get efficient: The VW Group showcased its next-gen W-12 engine [above and at top], which combines turbocharging and direct injection for the first time. It’s rated at 600 horsepower, served up at at 6000 rpm, and 664 lb-ft of torque from 1500 to 4500 rpm. The W-12 TSI is fitted with Bosch-Mahle–supplied turbochargers, and it comes with cylinder deactivation, which means it can operate as a VR6.
The W-12 TSI will be offered in several upcoming VW Group models. VW says that the engine will be optimized for off-road applications, but it will also be fitted in vehicles that can exceed 186 mph. Think Bentley Bentayga and next-gen Continental. The W-12 TSI will be offered in the next-gen Audi A8, as well, and we expect to see it in the next VW Phaeton, too. In the sedans, it’ll be rated at, VW says, 22 mpg on the European cycle. And, as an aside, VW added that every vehicle fitted with the new engine will have electric power steering.
Some engines, of course, are not all about power, and in the interest of fuel efficiency, Audi will launch a new 2.0-liter TFSI engine that will replace the current 1.8 TFSI; it will offer similar output of 170 to 200 horsepower but with far better efficiency. Look for it in the next-gen Audi A4; that combo was certified this month.
Both Hackenberg’s and Neusser’s speeches pointedly praised former supervisory-board head Ferdinand Piëch for his pioneering role in diesel technology. Like Winterkorn, Piëch didn’t show up in Vienna.
But he was as present as ever.
New Audi TFSI 2.0-liter four-cylinder engine
An almost forgotten piece of engine technology will help Audi’s next gasoline-powered A4 to slash its fuel consumption to near diesel figures while boosting power and acceleration. While Audi is couching it in different terminology—calling it a “new combustion method,” which it really isn’t—the German premium brand is essentially adapting Miller-cycle breathing technology to its ubiquitous EA888 four-cylinder powerplant.
The new engine was announced at Vienna’s annual Motor Symposium, and the technology will first be applied to a 2.0-liter, turbocharged, direct-injected gas unit making 188 horsepower and 236 lb-ft of torque and installed in the next Audi A4. Due on sale before the end of the year, the all-new A4 will slash the consumption figures of its predecessors—and, critically, undercut its competitors from Mercedes-Benz, BMW, and new class contender Jaguar—with a Euro-cycle combined fuel-economy figure of 47 mpg. By comparison, the BMW 320i, with a similar engine size, has a quoted European-cycle consumption figure of roughly 39 mpg (the more frugal 316i pulls that up by 1 mpg) and the best of the C-class Mercedes-Benz range, the C250, is at 44 mpg.
While refusing to stick the Miller-cycle tag onto its new engine, Ulrich Hackenberg, Audi’s board member for technical development, admitted “at its core, its principle is comparable to the Miller cycle. We are now taking a crucial step further with right-sizing,” he insisted. “Right-sizing involves the optimal interplay of vehicle class, displacement, output, torque, and efficiency characteristics under everyday conditions.”
2015 Audi A4 TDI (artist's rendering)
Our artist’s impression of the next Audi A4, which is due to be unveiled soon.
The Miller-cycle system was most famously used in production by Mazda’s Millenia, with its KZ-JEM 2.3-liter V-6, which ceased production in 2004. Mazda has kept an eye on the technology, though, and applied it recently on the Mazda 2. The system was the brainchild of American engineer Ralph Miller, who earned a patent for it on Christmas Eve, 1957. It works with both gas and diesel fuels and with two- and four-stroke cycles.
Typically, a Miller-cycle engine leaves the intake valve open on the compression phase longer than a normal engine. It operates in a similar fashion to the Atkinson-cycle engine, but uses forced induction (usually, but not always, a supercharger) to make up for the fuel-air mix forced out of the cylinder and through the open valve by the rising piston. The turbocharger helps the Miller-cycle engine to avoid power losses, even as it slashes fuel consumption by increasing the fuel-air mix in the cylinder after the intake valve closes.
For the EA888 engine, Audi has heavily changed the traditional intake period, shortening the duration from around 190 or 200 crankshaft degrees down to just 140 degrees. It also closes the intake valves later than normal, well after the bottom dead center. The expansion portion of the cycle is much longer than the compression phase to extract maximum work from every fuel-air mix.
The engine will capitalize on existing technologies to push the Miller-cycle philosophy even further, making use of the combination of direct and indirect (in the intake manifold) fuel injection and variable valve timing and lift already fitted to the EA888.
When the engine runs at part-throttle or low loads, Audi says it will deliver an extra fuel-injection burst from its indirect fuel-injection system before the air-fuel mixture even reaches the combustion chamber. It will then flesh this out with its existing systems. It also uses its existing variable valve lift to give the engine a short intake time on part throttle and up to 170 degrees of intake timing on full throttle or in heavy load situations.
This has helped broaden the spread of torque from the 2.0-liter TFSI four, with its 236 lb-ft peaking at 1450 rpm and holding steady until 4400 rpm. The 1984-cc, 309-pound engine also has its exhaust manifold cast integrally with its cylinder head and uses a very low-viscosity oil (0W-20) to minimize windage losses.
“Thanks to this right-sizing approach, the new engine enjoys the consumption benefits of a downsized engine in partial-load operation, while at higher loads it has the advantages of a large-displacement engine,” said Audi head of engine development Stefan Knirsch. “The result is optimal efficiency and performance characteristics across the entire engine-speed range.”
Il gruppo Vw ogni anno si presenta in forze al simposio motoristico di Vienna, d'altronde l'ex presidente di Vw Piech e' viennese ed è professore onorario dell'Università di ingegneria della città.
Audi introdurrà un nuovo 2.0 TFSI che promette notevoli risparmi.
C'è un nuovo W12 fsi per la Bentayga, futura continental, Phaeton e A8.
Un prototipo di 1.0 TFSI da 272 cv e un'ulteriore variante del 2.0 tdi da 300 cv.
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