As automakers introduce plug-in hybrids, each is trying to outdo the others.
Rivals battle over combined fuel economy, electric range, acceleration and recharging time.
Now it's "the button."
Specifically, on some upcoming plug-in hybrids, the driver will be able to keep the vehicle in electric mode or prevent it from using battery power.
"The button" is standard on the Opel/Vauxhall Ampera and Ford C-Max Energi, as well as plug-in hybrid versions of the redesigned Ford Fusion and Honda Accord. Ampera sales begin later this month, while the Ford and Honda models head to dealer lots late this year. A Volvo V60 powered by a diesel-electric plug-in hybrid goes on sale this year in Europe with "the button."
Mark Reuss, General Motors' North American president, wants to offer the feature on the Chevrolet Volt.
Reuss said GM was prevented from offering "the button" on the Volt in the United States because of an EPA issue for determining fuel economy when the car was certified. He did not elaborate. Meanwhile, the models sold in Europe have "the button." I spoke to Reuss last month at the Detroit auto show.
Before "the button," a plug-in hybrid's computer determined when the powertrain would run in pure electric mode, hybrid or rely on gasoline. The hands-off system analyzes vehicle speed, the driver's driving style and other factors to determine the best mode for optimum fuel economy and acceleration.
"The button" lets the driver determine the experience, for example, all electric in the city and gasoline on the highway. At some point, when the electric charge runs low, the system automatically switches to the hybrid or gasoline mode.
Which raises the obvious question: "Does the button improve fuel economy?
For example, if the driver keeps the vehicle in gasoline mode during highway trips and switches to pure electric in the city, will overall miles per gallon numbers increase?
They could, GM says, depending on the driver's skills at boosting mpg. But GM has no plans to tout "the button" as a fuel economy raiser.
It's simply a device to let drivers determine when they want to run purely in electric mode -- or not.