America has long had an obsession with cars. Drive-ins, drive-thrus, an extensive interstate highway system and cheap gas have all made it easy for consumers to incorporate large, fuel-hungry vehicles into their lives. Even though the fuel shortage of the 1970s managed to introduce the nation to smaller, more economical modes of transport, the love affair with practical didn't last very long. Once prices came back down to Earth, the "bigger is better" mentality returned and people were once again seduced by the promise of power.
In response, manufacturers looked for ways to deliver, and they developed technologies to please those who wanted more from their engines at the nudge of the throttle. But a funny thing happened on the way to additional horsepower: engineers discovered that some of these technologies -- like turbochargers and direct injection -- could not only increase an engine's power, they could also help it use fuel in a more efficient manner, without an overall increase in size or weight.
Flash forward to the past few years and gas prices that seem to go nowhere but up and Corporate Average Fuel Economy (CAFE) standards that require manufacturers to focus more on efficiency and emissions than on horsepower. In an effort to make timely products that address these concerns, car companies have begun to look at what technology they already have at hand. That's where Ford Motor Company enters the picture. The Michigan-based company has decided to move forward with a plan to place affordable turbochargers and direct injection in 500,000 of their vehicles by 2010, beginning in 2009 with the Lincoln MKS and the Ford Flex.
These "EcoBoost" engines, as Ford has dubbed them, will provide nearly 20 percent better fuel economy and up to a 15 percent reduction in CO2 emissions, according to the automaker. While these numbers aren't exactly on par with those of the hybrids and electric cars of the world, they do represent a significant step forward for gasoline engines. And because Ford foresees the more affordable EcoBoost engines selling in greater numbers than hybrids, for instance, their environmental impact has the potential to be broader, sooner.
More Performance, Less Engine
So, how do turbochargers and direct injectors work their magic to make a gasoline engine more environmentally friendly? To put it simply: together, they control the air/fuel mixture fueling the engine, which in turn makes it burn gas in a more efficient manner and allows it to be downsized without sacrificing power. A smaller engine equals less fuel and CO2 being released into the atmosphere.
A basic gasoline engine works by mixing air and gasoline in a cylinder, compressing the mixture with a piston, and then igniting it with a spark and using the resulting explosion to push the piston down, thereby powering the vehicle. Light-weight turbochargers use exhaust flow from the engine to spin a turbine and air pump, which in turn compress the air in each cylinder and allow more fuel to be added, thereby giving the engine more power when needed. With each cylinder more effectively packed with air, fewer are needed overall, which means that a V6 could have the same peak power as a larger, naturally-aspirated (non-turbo) V8, and would only require the same amount of fuel if the turbochargers kick in under heavier power demands. For example, when looking at a wide rpm range of 2,000-5,000 rpm, Ford says that its 3.5-liter EcoBoost V6 can deliver 340-plus lb.-ft. of torque, compared to 270-310 lb.-ft. of torque for a naturally-aspirated 4.6-liter V8, all while gaining two mpg. So, even though more power is produced by the EcoBoost engine, less fuel is needed and less CO2 is produced under normal operating conditions.
Efficiency is further optimized with direct injectors that tightly control the amount of fuel added to each cylinder, making each droplet more effective and helping to reduce lag and knock, common complaints of turbocharged engines of the past. In fact, when driving an EcoBoost engine, many people may never realize that they're driving a turbocharged engine at all. Those who had less-than-memorable experiences with turbos previously may find themselves pleasantly surprised by how the EcoBoost engines perform on the road.
Looking Down the Road
Ford describes EcoBoost as a near-term solution, one that will meet America's fuel economy needs until more of their diesels and hybrids hit the market as planned in the next few years. Furthermore, since EcoBoost engines incorporate technology that is relatively inexpensive, they will not carry a significant price premium, making the potential payback period much shorter than other fuel-sipping vehicles on offer.
While Ford and other automakers will continue to find new ways to improve fuel economy without hampering engine performance, the marriage of turbochargers and direct injection offers a way for today's consumer to have the best of both worlds without having to wait. And with diesel not readily available to all consumers and hybrids not always desirable, these "improved" gasoline engines like EcoBoost can be a cost-effective and practical choice for those who need something now.