2014 BMW i3 (German-market version), Amsterdam, Oct 2013Enlarge Photo
The 2014 BMW i3 electric car, which we drove last week, is generating intense interest among both plug-in proponents and BMW fans.
Among other things, it's the first car in the world offered with an optional range-extending engine, at an increased cost of $3,850.
But versions of the BMW i3 that are fitted with the range extender have been very specifically designed to meet California regulations on what it deems the "auxiliary power unit."
The APU, which maintains battery charge at about 30 percent after the pack has been depleted in normal use, is strictly limited in the additional range it can provide.
2014 BMW i3, 2013 Frankfurt Auto ShowEnlarge Photo
According to rules adopted in March 2012 by the California Air Resources Board (CARB), the 2014 BMW i3 with a REx unit fitted will be the first car to qualify as a "BEVx," or range-extended battery-electric vehicle.
That's described as "a relatively high-electric range battery-electric vehicle (BEV) to which an APU is added."
Not a plug-in hybrid
And it's quite a different animal from plug-in hybrids or an electric car like the Volt, which offers a gasoline range up to 10 times as long as its electric range before you have to refill the tank.
The objective, CARB says, is "not to develop a PHEV with universal appeal, but rather, to expand the market for BEVs by adding an option for a 'backup' APU and enable a class of near-ZEVs that achieve greater than 90 percent" reduction in emissions.
These vehicle offer "substantially more electric range than currently announced [plug-in hybrids], and ... electric range comparable to full-function battery-electric vehicles."
Those lesser vehicles are grouped in the "TZEV"--or transitional zero-emission vehicle--category. (NOTE: This definition modifies what was previously termed an enhanced advanced-technology partial zero-emissions vehicle, or eAT-PZEV).
Isn't regulation fun?
2013 Chevrolet Volt, Catskill Mountains, Oct 2012Enlarge Photo
Not a Volt, either
The TZEV description applies to both range-extended electric cars like the Chevy Volt and the growing number of plug-in hybrids, including the Ford C-Max and Fusion Energi models, the Honda Accord and Toyota Prius Plug-In Hybrids, and more to come.
But the BMW i3's designation as a BEVx imposes all-new and very specific requirements.
Summarizing from the lengthy 112-page regulation, 2012 Amendments to the Zero Emission Vehicle Regulations, the BEVx definition says (among other criteria):