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Toyota: EPA emission testing a barrier to new hybrids?
Sep 27, 2005 (From the CalCars-News archive)
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EPA Emission Testing Could Be 'Barrier' To New Hybrid Technologies

Source: Fuels and Vehicles [Sep 23, 2005]

SYNOPSIS: EPA fuel economy and emissions testing procedures could be a barrier to 'push-button hybrids', which would give the driver a range of driving-mode choices, from highly fuel efficient to one geared towards towing capability. A top Toyota official says that EPA fuel economy and emissions testing procedures could be a barrier to "push-button hybrids," which would give the driver a range of driving-mode choices, from highly fuel efficient to one geared towards towing capability.

Jim Press, chief operating officer of Toyota Motor Sales, explained to Inside Fuels and Vehicles that Toyota is working on a hybrid-vehicle technology that could operate much like a six-speed transmission where the driver chooses settings. One setting would allow for maximum fuel economy, such as a three-cylinder driving mode for highway cruising and another would provide the low torque needed for efficient towing. There could also be an optimum setting for maximizing fuel economy in stop-and-go, rush hour driving, which Toyota's blockbuster Prius hybrid has been calibrated for.

The problem would come when EPA looks to test the vehicle with the push-button, hybrid-electric technology, Press noted. "EPA is a barrier, what do you rate the fuel economy at?" Press likened it to when vehicles with paddle shifters for transmissions that blend automatic and manual transmissions. "Is it an automatic, or is it a manual" for fuel economy and emissions certification purposes, Press asked.

For a hybrid with a range of driving modes, each impacting fuel economy and emissions differently and under the control of the driver, establishing a baseline for EPA certification would be much more problematic. The current federal test procedure was established after extensive studies of typical driving patterns. It has come under assault lately because critics say it has failed to keep up with changes in these driving patterns.

While Press said that "a push-button hybrid is just my dream," he has clearly asked Toyota engineers about it, who responded they can't do it yet. But he noted it is only a software challenge. One Toyota engineer expanded on the concept saying the button could be a rheostat instead, acting like a volume control, providing an infinite range of fuel economy settings.

An official with EPA familiar with fuel economy and emissions certification explained just like the paddle shifter issue was surmounted, a testing protocol for vehicles with various hybrid mode settings could also be established if asked to do so.

Already Toyota's branded Synergy Drive, battery-electric hybrid vehicle technology allows for the driver to choose when the vehicle operates in electric-only mode. Prius cars sold in Japan and Europe have a button that when pushed engages only the electric motor. Because of battery pack limitations the all-electric drive function works for less than a mile. In the U.S. the function is disabled, in part because its use would distort EPA fuel economy and emissions testing results.

The all-electric drive function is crucial for customizers who are beefing up storage battery capacity and turning stock Prius hybrids into plug-in hybrids. The resulting vehicles can be recharged from the grid and can achieve fuel economy results approaching 100 miles per gallon.

The plug-in hybrid technology is being pushed by conservatives and liberals alike as a pathway to significantly reducing the oil consumption of the light-duty vehicle fleet in the U.S. So far the only large automaker that has shown any interest in the technology is DaimlerChrysler, which is applying the technology to a handful of its Sprinter vans. One of its motivations, company officials say, stems from concerned cities, particularly in Europe, that will close their centers to motorized traffic, allowing only zero-emissions vehicles like the Sprinter van when in all electric drive mode.


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