Volkswagen Shows “Micro Hybrid” and Dual-Fuel Three-Cylinder Engine

2015-10Best-VW logo

For years at Volkswagen, talk of efficiency improvements almost always involved TDI—the badging that denoted VW’s diesel technology, now effectively mothballed in the United States because of the company’s costly emissions scandal. It’s no surprise that this week at the Vienna Motor Symposium, the automaker showed several different paths that it sees leading to carbon-neutral mobility—with no mention of TDI.

One of these is the VW Golf TSI BlueMotion, powered by a new 1.5-liter TSI (turbocharged, direct injection) gasoline four-cylinder engine fitted with what the company describes as an “affordable micro hybrid system.”

What that amounts to is essentially an engine stop/start system with a significantly broader operating range. The new BlueMotion system employs the seven-speed version of VW’s DSG dual-clutch automatic transmission. If you lift gently off the accelerator, it simply declutches and disables the engine at speeds up to 81 mph. The setup is a little more complicated than it sounds, as it requires a higher-capacity battery—here a compact lithium-ion one—to handle the vehicle’s electric loads during long engine-off coasting stints. The battery is managed alongside a traditional lead-acid one, with a special Q-diode to isolate vehicle systems from the starter circuit. Three methods are used to restart the engine: by use of its starter motor, by re-engaging the clutch to crank the engine, or by combining the starter with clutch engagement.

Although the “hybrid-style characteristics” that VW says the new BlueMotion system provides might not constitute a hybrid by traditional definitions, it promises a boost of about 2 mpg, based on extremely optimistic European-cycle efficiency numbers (up to about 50 mpg, from 48 mpg).

The 1.5-liter TSI engine, which is being introduced in Europe this year, also has VW’s active cylinder management, which switches off two cylinders under light loads.

VW 3-cyl natural-gas engine

Volkswagen also revealed a new engine that will be offered in subcompact models: an 89-hp 1.0-liter turbocharged three-cylinder designed for compressed natural gas (CNG) but also capable of running on gasoline. When the engine is warm or under low load, it runs two cylinders on a rich mixture while one is on a lean mixture. That creates a more oxygen-rich exhaust stream from which the catalyst can more effectively convert methane.

The Shape of Things to Come? Not Quite

Both of these technologies are unlikely to be brought directly to the United States anytime soon, however. While Volkswagen does plan to bring the 1.5-liter TSI engine to the U.S. in a couple of years—in the next-generation Golf, among other products—it’s unlikely the coasting system would provide significant gains in EPA testing; nor is Volkswagen expected to go through the trouble of federalizing the little 89-hp triple.

What we can count on from Volkswagen in the U.S. instead is electrification—in forms that California and other ZEV Mandate states require, with designs previewed by the I.D. BUZZ, BUDD-e, and I.D. Crozz concept vehicles. There’s a new generation of traditional hybrids on the way, too.

While VW doesn’t have a lot of choice in some of its amends—including a 10-year Electrify America program—it’s making good on its own in a more stringent regulatory environment by investing $11 billion into advancing the fuel efficiency of its internal-combustion engines by up to 15 percent. That’s on top of more than $3 billion spent in the past five years. It’s as strong an indicator that we can have that, even for embattled Volkswagen, the internal-combustion engine sure isn’t dead yet.

from remotecar

Volkswagen Shows “Micro Hybrid” and Dual-Fuel Three-Cylinder Engine

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