The Joy of Driving Green
Carmakers aim to improve mileage and control emissions, while maintaining performance and luxury
Paul A. Eisenstein
From the Print Edition:
Dennis Haysbert, Nov/Dec 2006
Streams of sunlight pierce the forest canopy as we whip through California redwood country. Our lake blue Bentley Continental GTC convertible slips back and forth between shadow and light, the cool, yet fragrant air blasting in through the car's open top. The big V-12 purrs as we cruise, then roars menacingly as we slam the throttle to the floor.
A day's worth of hard driving has drained the tank. So, as we approach Mendocino, a warning light begins flashing ominously on the hand-tooled wood instrument panel. With the tank perilously close to empty, we ease off the gas and start looking for a service station. You might assume that, for a man sitting behind the wheel of a $180,000 automobile, money is no object, but as we pull up to the pump, my copilot can't help but let out an audible gasp. At $3.69 a gallon for premium, a fill-up will cost more than the bottle of Napa Valley Cabernet we were looking forward to splitting over dinner.
"Even the wealthy are feeling the pinch as oil prices soar to record levels," suggests Dan Gorrell, who until recently was the lead analyst for the California consulting firm Strategic Vision. And even those not stinging from the cost of filling up may bridle at contributing to global warming or our dependency on Mideast oil imports. More and more motorists, at every level of the socioeconomic spectrum, are becoming concerned about the issue of mileage. Fuel economy has become a critical factor for those buying a new car, according to industry data, whether they're in the market for a stripped-down Hyundai or a fully loaded Rolls-Royce Phantom.
The good news is that the industry is responding. Indeed, some of the most significant strides are being made in the luxury segment of the market, where buyers are generally more willing to absorb the cost of technology that can improve mileage and reduce harmful emissions. What's even more exciting is that these solutions often avoid the sacrifice normally associated with fuel efficiency.
BY THE NUMBERS
The all-new Lexus LS 460 sedan is a good example. Its new 4.6-liter V-8 puts out an impressive 380 horsepower, a whopping 100 hp more than the old LS 430. Yet the 2007 remake of the Lexus' flagship gains an additional mile a gallon in city driving and two more on the highway, according to the EPA sticker. Much of the credit should go to a trick dual-injection system. This unique approach, with both direct and port fuel injection, boosts fuel economy and performance simultaneously.
The '07 LS also boasts the world's first eight-speed automatic transmission. Six speeds are becoming the industry norm, and Mercedes-Benz recently launched a seven-speed in its redesigned flagship, the S-Class (see Good Life Guide, page 52). In the automotive world, bigger always seems to be equated with better. But do more gears really make a difference? Depends on what you do with them—and that's where microelectronics come in. If you're not careful, a transmission can spend a lot of time switching—hunting, in industry terms—between gears, especially if you're going up and down hilly terrain. Lexus, like Mercedes, has used some smart programming to anticipate what gear is best, whether you're cruising smoothly or driving balls-to-the-wall. Our own experience was that you're not likely to notice when the new LS 460 or the S550 shifts.
A number of Mercedes models—along with those from competitors such as General Motors—now feature a slick fuel-saving system that has been dubbed displacement-on-demand, or D.O.D. Your average V-8 engine has far more muscle than you actually need on the highway, unless you're pushing the limits on the autobahn. So why waste horsepower, or fuel? When power demands are low, D.O.D. shuts off one bank of cylinders in the engine of the new Cadillac Escalade SUV. Tip in on the throttle, though, and you're instantly drawing full power.
Jaguar takes a very different approach to blending performance and mileage with the XK, a sleek sports car that has an all-aluminum chassis and body. On paper, the base XK8 might seem to lag the competition, its 4.2-liter V-8 putting out only 300 horsepower in a segment where others are nudging close to 400 hp. But spend just a few minutes behind the wheel and you'll be convinced. The XK is a real contender. Lightweight aluminum means less mass to haul, so the V-8 doesn't have to work quite so hard. That translates into surprisingly good fuel economy: 18 mpg city and 27 highway.
The use of alternative materials, including aluminum, magnesium and even carbon fiber composites, is becoming increasingly common. Like the XK8, the Jaguar XJ has an aluminum chassis and body, as do several top-of-the-line Audi models, such as the A8 sedan. Expect to see these materials become even more common in the coming decade.
Drive anywhere in California these days, and you're likely to spot plenty of Priuses. Toyota's oddly shaped sedan has become the vehicle of choice for the green crowd, thanks to its gasoline-electric power train. By the mid-2007 model year, at least a dozen hybrid-electric, or HEV, models will be on the road. While some, such as the Honda Civic, are geared for the cost-conscious motorist, a growing number of hybrids are targeted toward the luxury market.
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