interesting article from the detroit press

August 24, 2007
BY KATIE MERX and MARK PHELAN
FREE PRESS BUSINESS WRITERS
Today General Motors Corp. executives will show off a new engine technology that could cut fuel consumption by up to 15%.
The savings are the product of an engine-transmission system known as homogeneous charge compression ignition, or HCCI, that marries the high fuel economy of a diesel engine with the relatively low emissions of gasoline engines.

With the potential to deliver better fuel efficiency than even some of its gas-electric hybrids, GM calls HCCI "the most awaited advanced combustion technology of the past 30 years." Mercedes-Benz soon will show its own version of the technology, though neither automaker has said when it will make them in production vehicles.
"By combining HCCI with other advanced gasoline engine and control technologies, we can deliver a good fuel savings value for consumers," Tom Stephens, group vice president for GM Powertrain and Quality, said in a statement. "It is another initiative in GM's advanced propulsion technology strategy to lessen our dependence on oil. ... I am confident that HCCI will one day have a place within our portfolio of future fuel-saving technologies."
GM is expected to demonstrate the HCCI combustion process today using two driveable concept vehicles, a 2007 Saturn Aura and a 2007 Open Vectra. Both vehicles are powered by modified 2.2-liter Ecotec four-cylinder engines. GM says the engines can generate 180 horsepower.
GM declined to say what fuel-efficiency figures the HCCI Saturn Aura might achieve in the Environmental Protection Agency tests that produce the window-sticker fuel economy figures automakers advertise.
However, a 15% improvement over an Opel Vectra currently on sale in Europe works out to be about 26 m.p.g. in the city, 43 m.p.g. on the highway and 35 m.p.g. in mixed use on the European Union's standard fuel economy test. That test is different from the EPA's procedure, but it suggests the HCCI engine would surpass the fuel economy of GM's 2008 Saturn Aura gasoline-electric hybrid.
"This truly is something different," said auto analyst Erich Merkle of IRN Inc.
David Cole, chairman of the Center for Automotive Research, agreed that it is a big deal.
"It's the kind of thing that will have a significant competitive dimension to it," Cole said.
GM's HCCI engine is among the first in a flood of high-efficiency powerplants automakers are developing to combine the high fuel economy of a diesel with the low emissions gasoline engines produce.
Mercedes-Benz plans to show an experimental engine that adds three more technologies to the concept for even higher fuel economy at the Frankfurt auto show in Germany next month.
Mercedes has not allowed journalists to test-drive any vehicle with its proposed engine yet, and will not say when it hopes to have the engine in production.
Mercedes' concept engine uses a turbocharger, an electric hybrid system and a variable compression ratio in a 1.8-liter four-cylinder engine. Mercedes calls the concept DiesOtto, a combination of the German names for diesel and gasoline engines. Mercedes says its engine could generate 238 horsepower and achieve 30 m.p.g. in a Mercedes S-class luxury sedan on the European test cycle that combines city and highway driving.
As automakers compete to be first to market with an HCCI engine, however, they continue to work on many other technologies as well, and GM is expected to introduce the 14 new or significantly revised powertrains it will make available in the 2008 model year.
Among the powertrains GM is expected to highlight today:
• The new two-mode hybrid system that will be available this year with a new 6.0-liter, V8 in GM's full-size SUVs. GM says the two-mode hybrid system delivers 332 horsepower and towing-friendly torque.
• Hybrid versions of its Saturn Vue, Saturn Aura and Chevrolet Malibu.
• Five new 1.0-liter and 2.0-liter engines for Europe, Asia and Latin America
• A new 3.6-liter V6 with direct injection for the Cadillac STS and CTS luxury sedans.
• Nine new six-speed transmissions that the automaker says will provide up to a 4% improvement in fuel savings and a 7% improvement in performance.
"For the most part, GM has a leg up on its competition in terms of fuel efficiency; they just get little credit for it," Merkle said. "They've really done some impressive things with fuel efficiency and performance."
Contact KATIE MERX at 313-222-8762 or [email protected].
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