GreenHybrid Referenced in US News & World Report
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08-29-2004, 11:06 AM
Diversions
Refiguring car fuel economy estimates
By Richard J. Newman
Like many new owners of the Toyota Prius, Margo Oge noticed something surprising once she began driving her new car last winter: Her gas mileage was well below the numbers listed on the sticker. The popular, pod-shaped Prius--a "hybrid" vehicle with an electric motor that augments the gasoline engine--is supposed to average about 55 miles per gallon. But she was getting less than 40.
That hit home. Oge is one of the top administrators at the Environmental Protection Agency, which sets the mileage figures for cars sold in the United States. And even she acknowledges that the problem is not the Prius's performance but her agency's tests. The EPA's methods for measuring fuel efficiency date to the 1960s and '70s and don't account for a lot of changes. Air conditioning and other new features consume extra energy. There's more traffic now, and driving habits have changed as people have moved to the suburbs. "We need to give more realistic information about fuel economy," Oge says.
Road tests. To measure how much government figures overstate actual fuel economy, U.S. News got out pencil and paper and tracked the mileage for a dozen new-model cars. The tests were unscientific, but consistent: Every single vehicle got worse mileage than the EPA says it should (chart, Page 90). On a 500-mile road trip with minimal traffic, for instance, the Infiniti QX56, a luxury liner of an SUV, averaged less than 15 miles per gallon--17 percent less than its EPA highway rating of 18 mpg. At our refueling price of $2.30 per gallon, that would add nearly $300 to the gas tab for a driver racking up 10,000 highway miles per year.
Economy cars underperformed too. The $15,000 Kia Spectra averaged just under 25 miles per gallon in mixed driving. That should have been closer to 28 mpg, the EPA's city/highway average. One of our test vehicles did come close to its potential. The Volkswagen Passat turbodiesel averaged 36.4 miles per gallon on a long highway trip, with the air conditioner on the whole way--slightly below its EPA highway rating of 38 mpg.
Under some conditions, the discrepancies between advertised and actual fuel economy may be larger for hybrids. Since hybrids rely on batteries for some of their power, they tend to get lower gas mileage in the winter--when Oge bought her Prius. Oge says her Prius now gets about 44 miles per gallon, and she loves it. On the website www.greenhybrid.com , run by a hybrid enthusiast who invites owners to post their mileage info, Prius owners report average fuel economy of about 49 miles per gallon, 11 percent less than the EPA's combined city-highway average. Honda's Civic hybrid averages 47 miles per gallon on the website, nearly even with its EPA rating for combined driving. Yet even Honda acknowledges it has received mileage-related complaints.
The EPA is now weighing how to come up with more realistic estimates. Its figures are derived by putting every car on a dynamometer, sort of a treadmill for cars, and simulating a 7.5-mile urban drive at an average speed of about 20 miles per hour, along with a 10.2-mile highway drive averaging about 48 mph. The EPA could simply change the test parameters, but auto industry officials argue that without better data about how Americans actually drive, such changes wouldn't offer much more clarity. At least car buyers know to be skeptical of claims they hear in the showroom.
Refiguring car fuel economy estimates
By Richard J. Newman
Like many new owners of the Toyota Prius, Margo Oge noticed something surprising once she began driving her new car last winter: Her gas mileage was well below the numbers listed on the sticker. The popular, pod-shaped Prius--a "hybrid" vehicle with an electric motor that augments the gasoline engine--is supposed to average about 55 miles per gallon. But she was getting less than 40.
That hit home. Oge is one of the top administrators at the Environmental Protection Agency, which sets the mileage figures for cars sold in the United States. And even she acknowledges that the problem is not the Prius's performance but her agency's tests. The EPA's methods for measuring fuel efficiency date to the 1960s and '70s and don't account for a lot of changes. Air conditioning and other new features consume extra energy. There's more traffic now, and driving habits have changed as people have moved to the suburbs. "We need to give more realistic information about fuel economy," Oge says.
Road tests. To measure how much government figures overstate actual fuel economy, U.S. News got out pencil and paper and tracked the mileage for a dozen new-model cars. The tests were unscientific, but consistent: Every single vehicle got worse mileage than the EPA says it should (chart, Page 90). On a 500-mile road trip with minimal traffic, for instance, the Infiniti QX56, a luxury liner of an SUV, averaged less than 15 miles per gallon--17 percent less than its EPA highway rating of 18 mpg. At our refueling price of $2.30 per gallon, that would add nearly $300 to the gas tab for a driver racking up 10,000 highway miles per year.
Economy cars underperformed too. The $15,000 Kia Spectra averaged just under 25 miles per gallon in mixed driving. That should have been closer to 28 mpg, the EPA's city/highway average. One of our test vehicles did come close to its potential. The Volkswagen Passat turbodiesel averaged 36.4 miles per gallon on a long highway trip, with the air conditioner on the whole way--slightly below its EPA highway rating of 38 mpg.
Under some conditions, the discrepancies between advertised and actual fuel economy may be larger for hybrids. Since hybrids rely on batteries for some of their power, they tend to get lower gas mileage in the winter--when Oge bought her Prius. Oge says her Prius now gets about 44 miles per gallon, and she loves it. On the website www.greenhybrid.com , run by a hybrid enthusiast who invites owners to post their mileage info, Prius owners report average fuel economy of about 49 miles per gallon, 11 percent less than the EPA's combined city-highway average. Honda's Civic hybrid averages 47 miles per gallon on the website, nearly even with its EPA rating for combined driving. Yet even Honda acknowledges it has received mileage-related complaints.
The EPA is now weighing how to come up with more realistic estimates. Its figures are derived by putting every car on a dynamometer, sort of a treadmill for cars, and simulating a 7.5-mile urban drive at an average speed of about 20 miles per hour, along with a 10.2-mile highway drive averaging about 48 mph. The EPA could simply change the test parameters, but auto industry officials argue that without better data about how Americans actually drive, such changes wouldn't offer much more clarity. At least car buyers know to be skeptical of claims they hear in the showroom.
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