The BMW i3 is an extended-range electric vehicle [EREV], which is basically an electric vehicle [EV] with an onboard backup generator, but just a little one.
For some people, who aren’t fully on board with the limitations of electric vehicles, such as the Nissan Leaf, with a range of about 75 miles, an EREV could be the next best thing. Chevy Volt is a good example of an EREV, which has an EV range of about 37 miles before the gasoline-powered range-extender kicks in. Having a range extender offers peace of mind to those who might otherwise think they’ll be stranded, but there are hundreds of Chevy Volt owners who’ve racked up upwards of 10,000mpg. In other words, they use their EREVs just like EVs. The BMW i3, a recently released EREV, does things slightly differently, and mostly to please CARB [California Air Resources Board] regulations.
As an EREV, the BMW i3 has the potential to be nearly emissions-free, but only if drivers use it like an EV and ignore the range-extender. Chevy Volt’s range-extender has a fuel tank that extends the range of the vehicle up to ten times that of the lithium-ion [Li-Ion] battery pack alone, but BMW i3’s 2.4gal fuel tank will only provide another 80-100mi range to the 22kWh contained in the Li-Ion battery pack. This effectively doubles the range of the vehicle, but also puts it into a special CARB category, BEVx [Battery Electric Vehicle eXtended].
With 80-100mi estimated EV range, the BMW i3 is already more capable than the Nissan Leaf’s 75mi range, but with a limited-capacity fuel tank, won’t go as far as the Chevy Volt. On the other hand, BMW i3’s CARB BEVx designation also means that it can get a free pass on California HOV [high-occupancy vehicle] lanes.