Stop-start saves fuel -- but not here; critics blame EPA test
Robert Davis, Mazda's top product-development executive in North America, wants to give stop-start a jump-start.
He says U.S. testing regulations prevent automakers from introducing fuel-saving technologies to this market.
In this case, stop-start technology, also known as idle-stop, has spread throughout the world -- just not here. The reason: The U.S. fuel economy testing cycle does not allow stop-start to work its magic, which means the miles per gallon benefit is not reflected in the official ratings.
Not sold in this country
These cars are sold overseas with stop-start, but the fuel-saving technology is not available on them in the United States.
• Audi A3 TDI
• BMW 1 series
• BMW 3 series
• Mazda3
• Mini Cooper
• Toyota Yaris
7% fuel savings
With stop-start, the car's engine is shut off when the vehicle is stopped and the driver applies the brakes. Releasing the brakes and touching the accelerator fire up the engine.
The problem: The EPA city-mode test cycle includes only one complete vehicle stop, so stop-start technology registers only a 0.1- or 0.2-mpg improvement, Davis said.
Since stop-start costs money to install, there's no marketing magic that will persuade people to pay the extra $500 Mazda would charge for the fuel economy gains that the EPA says don't exist.
"In Japan, we're seeing anywhere from 7 to 9 percent fuel economy gains from it," Davis said. "That's a jump from 33 to 37 miles per gallon in a metro environment."
He said Japanese consumers are so smitten with the technology that Mazda is selling nearly half of its Axela (Mazda3) and Biante (a small van) units with stop-start.
Relief could be on the way. The EPA is taking public comment on rule changes that could give cars with stop-start higher fuel economy ratings. A decision is expected in April.
Because the EPA is seeking input on its rule-making standards, Davis wants a united lobbying effort for a testing procedure that recognizes the benefits of stop-start.
Davis' pleas are obviously in Mazda's interest, but Mazda is far from the only automaker wanting to bring stop-start technology to the United States.
Volkswagen put start-stop in its Lupo hatchback in 1999, as part of its astounding 75 mpg rating. Since then others have developed systems -- mostly with diesel applications -- but have chosen not to offer them to U.S. customers for the same reason Davis outlined.
Mercedes-Benz has said it will have start-stop available on all engines by 2011 but has made no commitment for this market. This year Hyundai announced plans to bring start-stop to the United States but did not say when.
Audi of America spokesman Christian Bokich said: "We did not realize any savings in U.S. EPA estimates based on required testing cycles."
On hybrids only
Currently, the only vehicles using idle-stop in the United States are hybrids -- such as the Toyota Prius, Honda Insight, Chevrolet Malibu Hybrid and BMW ActiveHybrid X6 -- that use the technology as part of the hybrid powertrain's operating system. There is no U.S.-market vehicle that has stop-start with just an internal combustion engine.
Getting a useful measurement for stop-start's benefit may be easier said than done because Mazda's direct-injection technology works differently from other systems.
"We need to get some agreement," Davis said. "It needs to be industry-wide."
Source: Stop-start saves fuel -- but not here; critics blame EPA test
He says U.S. testing regulations prevent automakers from introducing fuel-saving technologies to this market.
In this case, stop-start technology, also known as idle-stop, has spread throughout the world -- just not here. The reason: The U.S. fuel economy testing cycle does not allow stop-start to work its magic, which means the miles per gallon benefit is not reflected in the official ratings.
Not sold in this country
These cars are sold overseas with stop-start, but the fuel-saving technology is not available on them in the United States.
• Audi A3 TDI
• BMW 1 series
• BMW 3 series
• Mazda3
• Mini Cooper
• Toyota Yaris
7% fuel savings
With stop-start, the car's engine is shut off when the vehicle is stopped and the driver applies the brakes. Releasing the brakes and touching the accelerator fire up the engine.
The problem: The EPA city-mode test cycle includes only one complete vehicle stop, so stop-start technology registers only a 0.1- or 0.2-mpg improvement, Davis said.
Since stop-start costs money to install, there's no marketing magic that will persuade people to pay the extra $500 Mazda would charge for the fuel economy gains that the EPA says don't exist.
"In Japan, we're seeing anywhere from 7 to 9 percent fuel economy gains from it," Davis said. "That's a jump from 33 to 37 miles per gallon in a metro environment."
He said Japanese consumers are so smitten with the technology that Mazda is selling nearly half of its Axela (Mazda3) and Biante (a small van) units with stop-start.
Relief could be on the way. The EPA is taking public comment on rule changes that could give cars with stop-start higher fuel economy ratings. A decision is expected in April.
Because the EPA is seeking input on its rule-making standards, Davis wants a united lobbying effort for a testing procedure that recognizes the benefits of stop-start.
Davis' pleas are obviously in Mazda's interest, but Mazda is far from the only automaker wanting to bring stop-start technology to the United States.
Volkswagen put start-stop in its Lupo hatchback in 1999, as part of its astounding 75 mpg rating. Since then others have developed systems -- mostly with diesel applications -- but have chosen not to offer them to U.S. customers for the same reason Davis outlined.
Mercedes-Benz has said it will have start-stop available on all engines by 2011 but has made no commitment for this market. This year Hyundai announced plans to bring start-stop to the United States but did not say when.
Audi of America spokesman Christian Bokich said: "We did not realize any savings in U.S. EPA estimates based on required testing cycles."
On hybrids only
Currently, the only vehicles using idle-stop in the United States are hybrids -- such as the Toyota Prius, Honda Insight, Chevrolet Malibu Hybrid and BMW ActiveHybrid X6 -- that use the technology as part of the hybrid powertrain's operating system. There is no U.S.-market vehicle that has stop-start with just an internal combustion engine.
Getting a useful measurement for stop-start's benefit may be easier said than done because Mazda's direct-injection technology works differently from other systems.
"We need to get some agreement," Davis said. "It needs to be industry-wide."
Source: Stop-start saves fuel -- but not here; critics blame EPA test
