The world's two largest automakers have gazed far into the future of internal combustion engines and seen a swirl of question marks.
Will an environmentally driven president someday push strict new limits on fuel consumption and emissions? Could the horsepower boom of the 1990s carry well into the new century? How can an automaker safely invest in new engines without being stranded if the market suddenly shifts?
No one knows how or when the market will change, but trends change faster than engine programs do. As automakers replace outgoing powerplants, they must commit now to a strategy they can live with for 20 years or more.
So Ford Motor Co. and General Motors are hedging their bets. Each has developed new, flexible engines that can serve them in green times and carefree times alike. And their new designs will let them shift their assembly lines from product to product without new investment or retooling.
The two automakers have spent at least $2 billion total creating these new families of engines. They promise to put more power into smaller, all-aluminum packages. And advances in technology will allow those smaller engines of tomorrow to do the job of existing engines today.
Under their plans, inline four-cylinder engines are poised to provide more power without spewing more emissions. The little-used concept of an inline-five will take on the job now being done by six cylinders. And a new inline-six from GM will challenge the big-power dominance of the current V-8.
Granted, in the big-gamble work of engine technology, Detroit's new engine concepts are just one horse in this race. Automakers worldwide are rushing to perfect new approaches to power, such as gasoline-electric hybrids and fuel-cell powertrains. In the coming decade those technologies could make Ford and GM's new approach look quaintly 20th century.
But standing at this point in history - when gasoline-powered internal combustion still rules the day - Detroit believes its best bet for the next 20 years is to invest in lighter, flexible engines that can deliver the same punch as the bigger engines they will replace.
Fritz Indra, executive director of advanced engineering for GM Powertrain, sums up the gamble: 'Will a four-cylinder or a five-cylinder engine with a turbocharger be able to replace an eight-cylinder engine, with respect to takeoff behavior? That is the principal development work that we are doing.'
GHOST OF THE FIREBIRD
As GM prepares to begin pilot production early next year at its new $500 million 'Vortex 4200' engine plant in Flint, Mich., the symbolism of the technological change is enormous.
The new factory stands on the site of an older GM engine plant. That plant - razed by GM - once churned out the booming V-8 iron-block engines for Corvettes, Firebirds and other muscle cars. The new plant will build all-aluminum, I-6s for light trucks.
Manufacturing advances in aluminum casting pioneered at Saturn Corp. will let GM 'cast in place' some parts that traditionally have required mounting with brackets. Filters and other extraneous components can be direct mounted without brackets, meaning fewer attachments and less weight.
As a point of comparison, the 4.3-liter V-6 used in the Chevrolet Blazer delivers about 190 hp. The new I-6, which displaces 4.2 liters, promises 270 hp - roughly the same as the 4.8-liter V-8 now powering the Chevrolet Tahoe. The new engine also will deliver 275 pounds-feet of torque vs. 250 pounds-feet from the 4.3-liter V-6.
The technology itself represents a major shift for GM. The V-block engines that have powered GM's vehicles since the 1970s are being replaced as GM returns to inline engine design. GM last used I-6s in its 1985 Chevrolet trucks. But starting next fall, the company will put aluminum I-6s into its new Oldsmobile Bravada, GMC Envoy and Chevrolet TrailBlazer mid-sized sport-utilities. GM's goal, says Ron Kaciba, chief engineer on the new I-6 program: 'To offer customers the power of a V-8 with the fuel efficiency of a six cylinder.'
IF 6 WERE 8
Does this make the V-8 an endangered species should the world get serious about global warming?
'The new engine approach will not mean the end of the V-8,' Indra vows. 'The V-8 also will have a lot of new technology coming along to improve its fuel efficiency.'
One technology Indra is promoting for GM's V-8s is cylinder deactivation. That would allow future V-8s to operate as six-cylinder engines most of the time. The other two cylinders are pulled into use for acceleration. The new Mercedes-Benz CL600 and S600 use the technology. Their 12-cylinder engines run on just six pistons when the driver is not accelerating, bringing a 20 percent savings in fuel, compared with a full-time 12-cylinder drive.
Indeed, engineers throughout the industry are looking for ways to turn down the gas burners without sacrificing power or driving comfort. They do not have much choice. Rising fears over global warming have raised the specter of stiffer regulations to curb fuel consumption and carbon dioxide emissions. Automakers are trying to seize the initiative themselves. GM and Ford, for example, have vowed to deliver 25 percent improvements in the fuel efficiencies of the sport-utilities over the next five years.
'There's no question that almost all of our technology is being driven by fuel efficiency,' says Rod Tabaczynski, Ford's director of powertrain and vehicle technology. 'Almost all of our engine plans are tied into higher fuel efficiency and lower CO2 emissions. It's really at the forefront of all of our plans. We don't make a change unless we can incorporate new efficiency figures at the same time.'
In late November, U.S. negotiators stared down the barrel of international pressure over a pending climate and emissions treaty in The Hague. The conference fizzled over disagreements - largely from the United States - over how to implement proposals that were part of the 1997 Kyoto Protocol to reduce fossil-fuel emissions globally.
But Kyoto has not gone away, despite last month's setback. Some observers predict that, if it materializes, the international treaty could force up the price of gasoline by 50 cents a gallon in this country.
It also could serve as a rallying cry for environmentalists, raising pressures to tighten vehicle fuel efficiencies or penalize big-engine autos.
Such real scenarios are in the minds of automakers.
The kind of flexible world engine family Ford has begun producing in Mexico addresses such concerns in two ways:
1. It gives Ford the flexibility to make rapid decisions about low-cost product changes without redesigning complex powertrains or retooling factories.
With flexible engine architecture, a single factory line can make either engine with the same machining tools and many of the same components, including valvetrains, pistons, cylinders, chains and sprockets.
2. The flexibility enables Ford to begin moving its fleet of vehicles to smaller-displacement, lower-emission engines without jolting consumers. Ford has spent $1 billion to put a new all-aluminum I-4 engine platform into production at two manufacturing sites. Its Chihuahua, Mexico, plant will build 1.8-liter and 2.0-liter versions of the new inline engine for Ford's European-built Mondeo.
A second plant, in Dearborn, Mich., will deliver a 2.3-liter version.
That version will replace the iron-block 2.5-liter engine that now goes into the Ranger pickup, shaving more than 80 pounds out of the truck.
Ford also plans to retool engine plants in Valencia, Spain, and Hiroshima, Japan.
The change in Ford's architecture will mean, for example, that the upcoming Ranger pickup will have a physically smaller four-cylinder engine, with 2.3 liters of displacement instead of 2.5, but will perform at more than 140 hp instead of the current 119 hp.
But what comes after the new four-cylinder reveals the depth of Ford's longer-range thinking.
In the next decade, the new aluminum architecture will permit 200 applications, including direct injection and variable valve timing.
There also will be an I-5 engine that produces power comparable to Ford's current V-6 engines, but at fuel consumption levels closer to those of a four-cylinder unit.
Neither Ford nor GM has revealed what it will do with its upcoming five-cylinder engines. But Tabaczynski theorizes Ford could use its five-cylinder powerplants in such applications as a mid-sized family car - the Taurus/Sable currently relies on a V-6 - or a compact truck.
In that scenario, a leaner burning five-cylinder would deliver the same power as a V-6. And since Ford sells nearly a half-million Taurus/Sables annually, such a change would help boost Ford's corporate average fuel economy ratings.
THE LOST CYLINDER
The rise of five-cylinder engines in an industry pumping on even numbers of pistons is a critical development in the greening of the auto industry. Five-cylinder engines also have emerged on the planning table at Saab Automobile AB, independently of parent GM's plans. And before Ford acquired Volvo Car Corp., five cylinders were embraced there, too.
But the five-cylinder is not a breakthrough in technology.
Some Audis had five-cylinder engines in the 1980s, and Honda Motor Co. used a five-banger in its short-lived Acura Vigor in the early 1990s. But in those days, Honda was still primarily a four-cylinder automaker.
Honda's issue was finding more displacement, not less. Its goal was to be taken seriously among its giant competitors.
Mike Spencer, spokesman for American Honda Motor Co.'s Acura Division, says the Acura five-cylinder 'was a great engine, but we went in another direction. It was great from a performance perspective. But from a sales and marketing perspective, it probably wasn't all we would have liked. You always got customers saying, `Five cylinders? What, did you lose one?' '
The other downside of a five-cylinder is mechanical. Most engineers prefer an I-6. Because of the symmetry of six pistons firing at equal intervals, the I-6 inherently runs smoothly.
BMW AG has built its image on silky-smooth I-6 engines. Shave off one cylinder, and that perfect balance is thrown off.
One solution is to add a balance shaft. A balance shaft rotates in the opposite direction of the crankshaft to balance out the shaking forces.
The new GM I-5s, when they go into production sometime during the next five years in Tonawanda, N.Y., will use two balance shafts to approximate the smoothness of an I-6. On the other hand, Volvo's I-5s do not use a balance shaft. Instead, the engines have external supports to absorb torque and rotation. 'A balance shaft is something to be avoided,' says Terry Hinderman, manager of engineering for Volvo Cars of North America Inc. 'It's just another device to cost money and absorb energy.'
HOW DOES IT FIT?
Engine designers also struggle with packaging. The shift to V-shaped engines in the 1970s was prompted by the industry's move to smaller vehicles with smaller engine compartments.
Inline engines are long and narrow. Vs are shorter, enabling them to be turned sideways under the hood for front-wheel-drive cars.
Inlines still face space limitations.
An I-6 will not fit into every vehicle, and GM's Indra acknowledges that adding an I-8 to the new GM modular architecture someday wouldn't be practical. But the simpler shape of the new I-6 and the upcoming I-5 will let GM make its add-on enhancements easier. Turbocharging is easier and cheaper on a straight engine because all the hardware can be placed on one side of the engine, instead of both banks of a V-engine.
That is what the industry is pursuing: the ability to produce more with less engine mass.
'The customer will never give up the comfortable drive and acceleration,' Indra says.
'The real task is to have more power and reduced fuel consumption. The companies will survive who can meet the future requirements on fuel consumption while still being fun to drive.'