In a post on GM’s FastLane blog, Pam Fletcher, Global Chief Engineer for Volt and Plug-In Hybrid Electric Powertrains, runs through GM’s current vehicle electrification options for consumers: the eAssist light electrification system; the extended range electric vehicle system for the Volt and the Cadillac ELR; and the battery-electric system of the Chevy Spark EV. (But no focus on “conventional” hybrids.)
Fletcher is responsible for the Extended Range Electric Vehicle propulsion system in the Chevrolet Volt as well as the propulsion systems in GM’s upcoming line-up of Plug-In Hybrid Elecrtic Vehicles.
As she outlined it:
eAssist provides a average 25% fuel economy improvement over a traditional internal combustion engine vehicle. GM estimates it will save a driver of a larger car about $1,850 a year in fuel. The technology is targeted for individuals who want a large sedan with compact car fuel economy, Fletcher said. eAssist is available on the Buick Lacrosse and Regal, as well as the Chevrolet Malibu and 2014 Impala.
GM is explicit that eAssist is not a hybrid system—petroleum is still the only fuel source. The small electric motor and lithium ion battery provide more power and give the car a little “boost”, under heavy accelerating. The boost comes from energy that is captured during braking and stored in the battery. eAssist technology also turns the engine off when the vehicle is idle to save fuel.
Drivers of the EREV Volt visit a gas pump every 900 miles or about every 6 weeks and pay only about $950 annually in fuel—an annual savings of $1,450 over a similar gasoline powered car, according to GM data.
The battery-electric Spark EV has a more constrained range, but could deliver about $1,800 annually in fuel costs, according to GM. The Spark EV is targeted at urban and suburban commuters and will initially be sold in California and Oregon.