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Fuel-Saving Mazda i-Stop Stalled In U.S. Because Of EPA Tests

 
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Mazda i-Stop

Mazda i-Stop

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Over several years, Mazda's i-Stop engine start-stop feature has helped owners in other markets to save on their fuel budget—and it's helped commuters in some of the most traffic-clogged areas be a little greener.

But the automaker has no plans to bring the technology—which, by some estimates, costs several hundred dollars per vehicle—to the U.S. Simply put, it's because the existing EPA test cycle, for gas mileage and emissions, doesn't show the benefits of start-stop systems.

"We can't find a way to show a monetary benefit for the consumer," said U.S. spokesman Jeremy Barnes, within the framework of the EPA fuel-economy numbers that appear on window stickers. In company tests, i-Stop affected the official EPA fuel economy test-test cycle results by barely more than a tenth of a mile per gallon.

The company's clever i-Stop systems don't use the starter to bring the engine back to life; rather, they stop the engine at a precise position so that it can be restarted by smartly applying fuel and spark at just the right timing to one, then more, cylinders, bringing it back to idle speed in just 0.35 seconds.

Mazda argues that the systems could make a significant difference in gridlocked urban areas where you regularly come to a complete stop—places like Manhattan, or Washington, D.C.—but at this time the EPA has no way of accounting for the stunning 10-percent improvement the system can yield in such driving.

2012 Mazda3 SkyActiv 2.0

2012 Mazda3 SkyActiv 2.0

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The automaker is making i-Stop one of the core technologies in its SkyActiv initiative, which gave its engineers a clean-slate approach to making its cars lighter, greener, and more fuel-efficient while still preserving the fun-to-drive qualities the brand is known for.

At this point, with the new EPA fuel economy standards framework (up through 2025) announced last week, Mazda, along with several other automakers, is hoping for incentives or credits that would make a system viable and competitive in the U.S. 

Porsche remains the only automaker with plans to offer start/stop in all its U.S. vehicles; the 2011 Porsche Cayenne and 2011 Porsche Panamera models—not just the hybrids—already come with the feature. BMW has also offered start-stop on several of its models in Europe but has balked at offering the feature in the U.S.

But arguably, the several-hundred-dollar cost of the components for a start-stop system are a significant issue for an affordable vehicle like a Mazda3.

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Comments (6)
  1. This is really a shame that such technology is stalled by a limits of the EPA tests. I drive in just such a traffic situation and would love this technology.

    Does anyone know if the AC works when the engine is stopped? Having the AC off in the Honda Insight at stop lights is a major limitation.
     
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  2. Thermoelectric AC/Heaters (TE HCVAC)would work with the engine off as well as with the electrically assisted vehicles or engine cars without engines such as the all electric or fuel cell cars. TE HVAC would elimiinate the refrigerant gas , R134a, which has 1300 times the "Greenhouse Gas Effect" as Carbon Dioxide (CO2), the primary Greenhouse Gas. Last year cars in the US released to the atmosphere 45 million metric tons of CO2 equivalent from AC through seal leakage and frontal collisions. Ford and GM are working to develop TE HVAC on a DOE project.
     
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  3. @John Fairbanks.
    Thanks for the info. I am still curious about the situation with this specific Mazda.
     
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  4. @John B., I'll see if I can find this out. I'm sure I can but it may take a little while. I will note that the OEMs my company is working with on start-stop systems are generally not open at all to no A/C. The main method may be a hydraulic accumulator that is powered by a small DC brushless motor. Even if the engine is off, there is enough pressure to power the AC and other auxilliary options. That's one common approach. But because most of our start-stop business now is in Asia, I'm not 100% there techncially yet, either, just getting there gradually.
     
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  5. Thermoelectric AC/Heaters (TE HCVAC)would work with the engine off as well as with the electrically assisted vehicles or engine cars without engines such as the all electric or fuel cell cars. TE HVAC would elimiinate the refrigerant gas , R134a, which has 1300 times the "Greenhouse Gas Effect" as Carbon Dioxide (CO2), the primary Greenhouse Gas. Last year cars in the US released to the atmosphere 45 million metric tons of CO2 equivalent from AC through seal leakage and frontal collisions. Ford and GM are working to develop TE HVAC on a DOE project.
     
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  6. @John B. I work for a supplier that makes motors for these types of systems (one reason I laugh at the ridiculously low estimated cost of reaching CAFE standards) and this obvious concern is being dealt with in different ways by different OEMs. Some systems would turn back on automatically after a set period, others would use alternative heating technologies like John F. mentioned, etc... Nobody wants to achieve higher mileage/lower emissions at the cost of freezing or burning up in traffic...
    There has been talk for 2-3 years of having the EPA finally revise the cycle itself and the OEMs obviously support this, but still nothing.
    Thanks to John F. for your comments as well.
     
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