BMW Balances Horsepower and MPG
As the auto industry scrambles to produce vehicles with greater efficiency, each firm is developing its own strategy and its own way to market its tactics. BMW uses “Efficient Dynamics” to describe its approach, which has a nice ring but has lacked much substance.
But a sneak peek of BMW’s upcoming 2009 7-Series sedan in Mirimas, France, gave a small group of journalists a chance to learn what efficient dynamics really means.
The core concept is to combine world-class drivability—BMW’s trademark—with exemplary emissions management and fuel-saving technologies. There are seven primary areas tactics:
- Drivetrains optimized for clean combustion
- Lighter weight construction, such as aluminum doors and side panels
- Regenerative braking to supply and store energy
- Electric power steering for greater efficiency compared to hydraulic systems
- Air vent controls to enhance aerodynamics and reduces air resistance
- Gear shift indicators informing the driver when to upshift or downshift for maximum efficiency
- Low-resistance tires
One item not on the list is cutting back on power. The next generation BMW 7-Series will arrive in the United States next spring with a new, more powerful 4.4-liter V8 engine outputting 400 horsepower—40 more horses than the current model. Many would argue that increasing performance—especially to 400 horsepower—runs counter to efficiency goals. But BMW is trying to do at least two things at once: boost power efficiency and give drivers an exciting ride, hence the code name of “efficiency dynamics.”
In the case of the new BMW 7-Series, the resulting fuel economy is approximately 21 miles per gallon in the EU test cycle. Compare that to the current 7-Series’ combined 18 miles per gallon with a significantly less powerful engine. “The idea is that efficiency and dynamics are not mutually exclusive components. Advancing one should not adversely affect the other,” said Dr. Klaus Draeger, BMW project leader and board member, in an interview with Hybridcars.com.
BMW is not claiming that the 7-Series is the poster child for green motoring, but, at the very least, it indicates BMW’s direction for future products. With its approach, smaller models like the 3-Series, which currently gets around 22 miles per gallon, the level of efficiency could jump to the subcompact neighborhood, somewhere above 30 miles to the gallon. BMW’s start-stop system has already been added to the 1-series and some 3-Series models overseas and could be available in the U.S. by next year. There has also been speculation about a 7-Series hybrid in the next two years—but BMW is staying quiet about a full hybrid gas-electric system.