Wednesday, February 14, 2007

How to meet a higher CAFE

BUSH ENERGY PLANBush's shocker: How to meet a higher CAFE

Richard Truett Automotive News 1:00 am, January 29, 2007
First the good news: In theory, automakers can meet President Bush's call to improve fuel economy simply by commercializing off-the-shelf technologies. But it's going to cost plenty. If light-vehicle CAFE standards rise by a third by 2017, to 34 mpg, as President Bush proposed last week, we'll see a more small cars, diesels and hybrids.Here are the technologies that could deliver big gains in fuel economy, along with ratings for practicality and cost. A score of 5 five means the technology could be on your driveway soon. A rating of 1 means the technology is the modern equivalent of the 100-mpg carburetor.We grade these technologies on the curve. No "pass-fails" here!
TURBOCHARGERS: In Europe, automakers improve mileage by shrinking the engine, then adding a turbocharger or supercharger.
Volkswagen uses both devices on the 1.4-liter gasoline engine in the European version of the Golf GT. The results: A 0-to-60 mph time of about 7.6 seconds, and close to 50 mpg on the highway. GM has installed a smaller but more powerful engine in its Pontiac Solstice and Saturn Sky roadsters. The 2.0-liter turbocharged four-cylinder engine gets better fuel economy than the base 2.4-liter engine. Practicality: 4. These technologies are proven and easy to install.Cost: 3. Turbochargers and superchargers can add $1,000 or so to a vehicle's price.
Best betsHow various fuel-saving technologies are likely to fare.Winners: Turbochargers, diesels, starter generators, efficient transmissionsThe jury is out: Lightweight materials, plug-in hybridsNot in this lifetime: Fuel cells
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DIESEL ENGINES: Diesels can improve fuel economy by about 30 percent, and German automakers are vigorous in promoting their use in cars and SUVs. In the past, diesels were the province of heavy-duty pickups. Now that low-sulfur diesel fuel is available, diesels are poised for a comeback.
Practicality: 5. Many vehicles sold in the United States today are available elsewhere in the world with a diesel.Cost: 2. The big challenge is reducing the cost of the emissions system so diesels can be sold profitably in small cars.
LIGHTWEIGHT MATERIALS: Ford engineers once calculated that they could improve fuel economy by 1 mpg for every 150 pounds shaved off the Explorer. But Ford never actually cut the weight.
Maybe it's time to give lightweight materials such as carbon fiber and aluminum another look. On the Audi A8 and Jaguar XK, the aluminum unibody has saved hundreds of pounds. The A8's body weighs 475 pounds, about half as much as it would if it were made of steel. Automakers commonly use aluminum for hoods and trunks. Lightweight carbon fiber also is appearing on a growing number of vehicles.Practicality: 3. Plastics, magnesium, aluminum and other lightweight materials are becoming more popular.Cost: 3. Aluminum remains expensive, while carbon fiber and magnesium are reserved for pricey exotic cars.
STARTER GENERATORS: Engineers are finding ways to reduce the engine's workload.
Last fall, GM launched the Saturn Vue hybrid with an alternator that doubles as a starter and returns energy to the battery when the driver brakes. It improves fuel economy on the Vue Greenline by 20 percent over the standard model. The Vue Greenline costs $1,995 more than the regular model. Other energy-saving devices include electric power steering, which uses less energy, and reduces weight by eliminating the hydraulic pump and lines. Other ways to save energy include regenerative brakes, which recharge the battery when the vehicle is slowing down. BMW is pioneering these technologies, which can boost fuel economy by 8 percent. Practicality: 5. The race is on to make components more efficient.Cost: 3. Items such as regenerative brakes require costly redesigns.
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EFFICIENT TRANSMISSIONS: In most vehicles, six-speed automatics and continuously variable transmissions boost fuel economy about 6 percent. But they add $750 to $1,500 to the price of a vehicle with a standard five-speed manual.
Practicality: 5. A record number of CVTs and six-speed transmissions are available in vehicles today.Cost: 3. Premium vehicles will get highly efficient transmissions first. When economies of scale drive down costs, the technology will migrate into less expensive vehicles.
PLUG-IN HYBRIDS: A production version of the Chevrolet Volt could get the equivalent of 150 mpg if the owner recharges its batteries at night with relatively low-priced household current.
Other hybrids, such as the Toyota Prius and Ford Escape, could also see dramatic gains in fuel economy if they are retrofitted with plug-ins to allow recharging.Practicality: 2. The engine technology is achievable, but battery makers have yet to develop reliable lithium ion batteries.Cost: 2. Like any hybrid, plug-ins need two power sources -- the battery and the gasoline engine -- to provide acceptable performance. A conventional hybrid typically carries a $3,000 premium. A car like the Volt, which would require pricey lithium ion batteries and plug-in technology, would cost even more.
FUEL CELLS: Practicality: 2. Engineers have solved many technical hurdles, and test vehicles are on the road. But automakers must improve their durability, and gas stations would have to be retrofitted to supply hydrogen for the fuel cells.Equally critical, the production of hydrogen will require massive amounts of electrical power, much of it probably from nuclear power plants that aren't even on the drawing boards yet.Cost: 1. Each fuel-cell test vehicle costs $1 million or more. They are at least a decade away from being cost effective.Now that we've rated these technologies, we will offer a caveat on our grades. If Congress approves a steep increase in fuel economy, automakers inevitably will speed up introduction of these technologies.One way to improve CAFE would be to manipulate the marketplace: Raise the price of big trucks and other gas hogs, then lower the price of smaller, more fuel-efficient vehicles. In the world of CAFE, this is a time-honored technique.So maybe we'll have to switch to pass-fail grades after all.You may e-mail Richard Truett at

The Audi A8's aluminum body weighs 475 pounds, about half as much as a steel body. A 2007 model is shown.
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