These developments are just a suggestion of what's to come, says Stephens, as GM plans to roll out 50 new, more efficient and more powerful engines and transmissions by the end of the decade.
GM's overall goal, says Stephen, is "to reduce emissions and improve fuel economy as the company marches toward the long-term goal of producing hydrogen fuel-cell-powered vehicles to remove the vehicle from the environmental debate."
But we're maybe a decade or more away from governments not having the auto industry to kick around any more, so Stephens and GM and cranking away on improving the bridge technology.
One of the things that excites Stephens the most is something called Homogenous Charge Compression Ignition (HCCI), which is an ultra-advanced combustion system and might be workable in a couple of years.
HCCI is a combustion technology that uses compression ignition rather than spark ignition to initiate the combustion process, and that means higher efficiency and lower NOx emissions compared to a normal spark-ignition or diesel engine.
"The technologies we are developing today -- gasoline direct injection, Displacement On Demand, variable valve actuation and variable valve timing -- all deliver incremental improvements to engine efficiency," says Stephens. "But more importantly, they are the building blocks to mass-producing engines that can operate with advanced combustion systems like HCCI."
Short-term, says Stephens, "multiple variants of the new small-block engines feature Displacement On Demand, as well as variable valve timing (VVT). Displacement On Demand seamlessly alternates the engine between eight- and four-cylinder operation, improving engine efficiency by as much as 12 percent in some vehicles."
Variable valve timing optimizes engine performance by continuously adjusting intake and exhaust valve timing in relation to the crankshaft. The introduction of variable valve timing in these engines is the industry's first application of VVT on a mass-produced V-8 overhead valve engine.
Complete details of the new engine variants will be available in mid-September, by the way.
In addition to improving engine efficiency, GM is launching a broad portfolio of advanced six-speed automatic transmissions to increase overall powertrain performance.
"During the next five years, GM will launch 10 new automatic six-speed transmission variants," says Stephens. "In fact, by 2010, GM will be producing more than three million six-speed transmissions per year."
GM six-speed automatic transmissions will use a wide gear ratio spread to improve both performance and fuel economy over traditional four-speed automatics, Stephens notes, in an effort to please the congregations of what traditionally are disparate places of worship.
GM will launch seven of the six-speed automatic variants in North America and Europe.
In addition to improving the efficiency of conventional engines and transmissions, GM is also in the midst of rolling out three hybrid powertrain systems. "The company plans to integrate the systems in up to 12 vehicle models," says Stephens, "providing consumers a broad portfolio of hybrid systems that will vary in fuel economy savings and cost."
"Through the last 30 years in North America, we've improved our gasoline car fuel economy by as much as 130 percent and our gasoline truck fuel economy by as much as 75 percent," says Stephens. "We'll continue this trend of significant improvements by applying these and other engine and transmission technologies around the globe."
Say Amen, somebody.
photo:General Motors
GM's overall goal, says Stephen, is "to reduce emissions and improve fuel economy as the company marches toward the long-term goal of producing hydrogen fuel-cell-powered vehicles to remove the vehicle from the environmental debate."
But we're maybe a decade or more away from governments not having the auto industry to kick around any more, so Stephens and GM and cranking away on improving the bridge technology.
One of the things that excites Stephens the most is something called Homogenous Charge Compression Ignition (HCCI), which is an ultra-advanced combustion system and might be workable in a couple of years.
HCCI is a combustion technology that uses compression ignition rather than spark ignition to initiate the combustion process, and that means higher efficiency and lower NOx emissions compared to a normal spark-ignition or diesel engine.
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| Chevrolet Corvette Z06 (Photo: General Motors) |
Short-term, says Stephens, "multiple variants of the new small-block engines feature Displacement On Demand, as well as variable valve timing (VVT). Displacement On Demand seamlessly alternates the engine between eight- and four-cylinder operation, improving engine efficiency by as much as 12 percent in some vehicles."
Variable valve timing optimizes engine performance by continuously adjusting intake and exhaust valve timing in relation to the crankshaft. The introduction of variable valve timing in these engines is the industry's first application of VVT on a mass-produced V-8 overhead valve engine.
Complete details of the new engine variants will be available in mid-September, by the way.
In addition to improving engine efficiency, GM is launching a broad portfolio of advanced six-speed automatic transmissions to increase overall powertrain performance.
"During the next five years, GM will launch 10 new automatic six-speed transmission variants," says Stephens. "In fact, by 2010, GM will be producing more than three million six-speed transmissions per year."
GM six-speed automatic transmissions will use a wide gear ratio spread to improve both performance and fuel economy over traditional four-speed automatics, Stephens notes, in an effort to please the congregations of what traditionally are disparate places of worship.
GM will launch seven of the six-speed automatic variants in North America and Europe.
In addition to improving the efficiency of conventional engines and transmissions, GM is also in the midst of rolling out three hybrid powertrain systems. "The company plans to integrate the systems in up to 12 vehicle models," says Stephens, "providing consumers a broad portfolio of hybrid systems that will vary in fuel economy savings and cost."
"Through the last 30 years in North America, we've improved our gasoline car fuel economy by as much as 130 percent and our gasoline truck fuel economy by as much as 75 percent," says Stephens. "We'll continue this trend of significant improvements by applying these and other engine and transmission technologies around the globe."
Say Amen, somebody.
photo:General Motors