Chevy Technology Series Part 2: Propulsion
THE NEXT PROPULSION CHAPTER
In our Powertrain chapter, we took you on a tour of the past, present and near-future powertrains that motivate the Chevrolet lineup, from the legendary small block V8 to the gutsy but gas-sipping turbocharged 4-cylinder in Chevrolet’s smaller cars.
Which likely raised the question: What’s next? Let’s look to alternatives to the conventional gasoline-powered internal combustion engines — some using those engines as part of a more sophisticated package in vehicles like Volt, along with additional technologies that are available right now, such as the eAssist system offered in the Chevrolet Malibu Eco — and the funky, innovative answers to the next-generation transportation challenges with concept vehicles like the Chevrolet EN-V.
A Multi-Tech Approach
This search for future solutions isn’t something we’re taking for granted. “There is no single solution for improving fuel economy,” says Mary Barra, General Motors senior vice president, Global Product Development. Since there is no silver bullet, the solution is likely to be found in a combination of technologies, which is why our advanced research ranges from ultra-advanced aerodynamics to space-age construction materials; from the next generation of lithium-ion batteries to hydrogen-powered fuel cells that don’t rely on a drop of gasoline.
Volt: Extended-Range Electric
Jimmie Johnson’s office is the cockpit of a 200-mph Chevrolet Impala race car that he drives for the Hendrick Motorsports team. But off duty, one of the five-time NASCAR Sprint Cup Series™ champion’s favorite cars is his 2011 Chevrolet Volt— a vehicle he uses for personal transportation for himself, wife Chandra and their daughter, Genevieve Marie, who turns two in July. Johnson can afford to drive whatever he wants, but he chose Volt for its combination of safety, energy efficiency and — yes — performance.
“It has all the amenities, the same comfort level everyone is used to in a car — rear camera, a great sound system — and great acceleration and handling. It’s a car you can drive every day. I find I become more aware, more conscious of my energy use when I’m driving my Volt — I try to complete all my errands without having the gasoline generator engine kick in.
“When I drive from my home to the Hendrick race shop, I’ll try to make it there and back on electric power alone — it kind of becomes a challenge. And if I’m smart and there isn’t a lot of traffic, I can make it all the way without the generator firing up.” Johnson has a 240-volt charging station in his garage — “I just pull up, plug in and I’m set.”
Johnson isn’t alone in the NASCAR ranks as a Volt owner — fellow NASCAR Sprint Cup Series driver and Indianapolis 500® winner Juan Pablo Montoya bought a Volt which he says is “comfortable, very quiet and has great acceleration.”
“A lot of attention was paid to maintaining a fun-to-drive level of ride and handling,” says Al Houtman, Volt vehicle performance manager. Compared to most other electrics and hybrids in the mainstream market, the experience of driving Volt “is very different, very refined.”
The viability of the concept was proven early on, says Mike O’Leary, lead development engineer for Volt. “We had a unique concept — the first extended range electric car — but our goal was to deliver it to customers doing everything their car today can do, but still able to run off the grid, so to speak. We tried to make sure there were no sacrifices on either side. Yes, it has electric capability, but there is no sacrifice to get that.”
Volt offers an EPA-estimated 94 MPGe (electric); MPG 35 city/40 highway (gas).
Tahoe and Silverado: Hybrid Electric Technology
The general conception is that hybrid electric technology is just for smaller vehicles, but Chevrolet has been disproving that theory since the introduction of the Hybrid Silverado pickup and Tahoe SUV. The seamless, sophisticated system increases fuel economy, but maintains excellent power and drivability. With an EPA-estimated 20 MPG city and 23 on the highway, Tahoe Hybrid and Silverado Hybrid serve up 332 horsepower and 367 lb.-ft. of torque.
Fuels Down the Road
With an EPA-estimated 42 MPG, Cruze Eco has the best highway mileage of any gas engine in America. But in Europe, the diesel-powered Cruze has been a sales success, so Chevrolet will begin selling Cruze here with an optional diesel 4-cylinder engine in 2013. General Motors engineers in the U.S. have been working closely with engineers in Europe, including the GM Powertrain Facility in Torino, Italy, to develop the engine. General Motors sold more than 500,000 diesel-powered vehicles outside the U.S. in 2011 — Chevrolet customers will have the opportunity to find out why next year.
For Chevrolet heavy-duty truck customers, diesel power remains the gold standard. The 6.6-liter Duramax® Diesel is rated at 397 horsepower, with a startling 765 lb.- ft. of torque. Coupled with the Allison® 1000 6-speed automatic transmission, the diesel-powered Silverado HD can tow up to 23,000 pounds with a fifth-wheel or gooseneck hitch, depending on the truck’s features. The powertrain is also offered in the Chevrolet Express 3500 Cargo Van. All Duramax engines offer B20 biodiesel capability too.
Chevrolet will offer a bi-fuel system in the 2013 Silverado 2500HD Extended Cab, which allows the 6.0-liter V8 engine to operate on either gasoline or compressed natural gas. Unlike aftermarket CNG conversions, Silverado with CNG capability will have full Chevrolet warranty coverage. The system is already available on Chevrolet Express Cargo Vans.
“The bi-fuel truck provides businesses with refueling flexibility and eases consumer range concerns that typically come with CNG, all while reducing emissions and controlling costs,” says Joyce Mattman, director of GM commercial product and specialty vehicles. The engine can seamlessly transition between CNG and gasoline — combined, the truck will offer a range of more than 650 miles.
Regardless of the politics surrounding ethanol as a supplement to — or a replacement for — gasoline in passenger vehicles, there’s no denying it is a viable, reliable alternative to gasoline. General Motors and other companies have been working on systems that could develop ethanol from sources such as agricultural, forest and municipal waste. There are more than 2.5 million E85 FlexFuel Chevrolet vehicles on the road today, and Chevrolet offers more E85 FlexFuel-capable vehicle choices than any other brand.
Hydrogen-Powered Fuel Cell
In 1966, GM was the first to use fuel cells to power the wheels of a vehicle. In 1997, GM displayed its first modern-era fuel cell vehicle propulsion concept at the Geneva
Motor Show, and a year later at the Paris Motor Show, GM debuted its first drivable fuel cell vehicle. In 2007, as part of its ongoing fuel cell research, GM instituted
Project Driveway, an initiative that put test vehicles in the hands of public and private entities, and it soon became the world’s largest market test of hydrogen-powered fuel cell electric vehicles. By 2009, Project Driveway had accumulated a million miles in real-world driving. This fleet now has more than 2.5 million accumulated miles and is still on the road.
Most recently, the project has been concentrating on the development of a production-intent hydrogen fuel cell system that can be packaged in the space of a traditional 4-cylinder engine. The system is half the size, 220 pounds lighter and uses about a third of the platinum of the system in the Chevrolet Equinox fuel cell electric vehicles used in Project Driveway.
And though it may be outside the pure vehicle development role manufacturers usually play, General Motors is part of an initiative in Hawaii, where GM and its partners are evaluating methods to distribute hydrogen through existing natural-gas pipelines, addressing the long-standing problem of how to cost-effectively produce and distribute hydrogen.
Malibu Eco: eAssist
The most fuel-efficient midsize Chevrolet ever, Malibu Eco began that journey with solid conventional engineering — lightweight aluminum wheels, effective aerodynamic design, low rolling resistance tires — and coupled with the innovative eAssist “light electrification” technology, offers an EPA-estimated 25 MPG in the city and 37 on the highway with no compromise to performance.
In fact, eAssist boosts performance with a state-of-the-art lithiumion battery and an electric motor-generator to enable regenerative braking electric assist and start-stop capability. The package weighs only 65 pounds and is able to give the Ecotec® 2.4-liter 4-cylinder gasoline engine a boost of up to 15 horsepower via the 15-kW motor-generator.
“The battery system is designed to provide power assistance to the internal combustion engine, rather than storing energy for all-electric propulsion,” says Steve Poulos, global chief engineer for eAssist. “It’s really an extension of the conventional internal combustion engine, not a replacement for it.”
But eAssist isn’t the only technology that makes the 2013 Chevrolet Malibu Eco a gas sipper. Located in the lower grille, its “active shutter system” automatically closes airflow through the lower intake opening when maximum airflow isn’t needed. When closed, the shutter system enhances aero performance by redirecting airflow around the front of the vehicle and down the sides, rather than through it. Also, the outside rearview mirrors are designed to maximize efficiency as are the unique taillamps. Four underbody panels cover approximately 50% of the lower portion of the vehicle and provide a cleaner airflow path beneath the vehicle. Lightweight components and systems, including an aluminum hood aluminum rear bumper beam, dissipative carpet and dash mat, and more, generated about 130 pounds in weight savings.
Bottom line: “It’s a very integrated powertrain system with no compromises in driving performance, shift quality or ride and handling,” says Todd Stone, Malibu lead development engineer. “We believe this combination points to the future of vehicles powered primarily by an internal combustion engine.”
Spark: All Electric EV
Chevrolet’s smallest car in the U.S., the Spark, was designed with efficiency in mind. But Chevrolet will introduce an all electric Spark EV that, in 2013, will be offered in limited numbers in select global markets, including portions of the U.S., most notably California.
“The Spark EV offers customers living in urban areas who have predictable driving patterns or short commutes an all-electric option,” says Doug Parks, global vehicle chief engineer for electric vehicles at Chevrolet. Spark EV will be powered by a 114-horsepower, 85-kW permanent magnet motor that will be built in the U.S.
While the original pod-like EN-V is something of a flight of fancy, the next-generation Chevrolet EN-V, currently in development, adds a lot of the features necessary to make it a true alternative to current transportation, including climate control and storage space.
“The Chevrolet EN-V has the potential to reinvent transportation in key markets by creating a new-vehicle DNA through the convergence of electrification and connectivity,” says Chris Borroni-Bird, GM director of advanced technology vehicle concepts. “It provides an ideal solution for petroleum-free and emissions-free urban transportation that is free from congestion and crashes, and is more fun and fashionable than ever before.”
Regardless of the technology that may emerge as dominant – hybrid, electric, hydrogen, diesel, biofuels – it is already well-established on Chevrolet’s global radar. As the current product lineup suggests, we’re already well on our way to the Next Big Thing.
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