2014 Cadillac ELREnlarge Photo
Not all plug-in electric cars rely on battery power alone; some also have gasoline engines as backups, for longer range or more power.
Last year, we identified six plug-in hybrid vehicles on sale during 2013.
This year, the list gains three new entries (from BMW, Cadillac, and Mitsubishi) and loses one (the Fisker Karma).
Note that we're lumping into this category cars with two different types of drivetrains.
First are the plug-in versions of conventional hybrids, including the Ford's C-Max Energi and Fusion Energi models, the Honda Accord Plug-In Hybrid, and the Toyota Prius Plug-In Hybrid.
Then there are the range-extended electric vehicles, in which only electricity powers the wheels and the engine runs a generator that produces electricity for that purpose.
Those cars include the upcoming BMW i3 ReX, the Chevy Volt, its platform twin the Cadillac ELR, and the now-departed Fisker Karma.
Then there's the Mitsubishi Outlander Plug-In Hybrid, which can work either way. (The Accord Plug-In Hybrid can act either way too, but it's adapted from a conventional hybrid).
With that little bit of education out of the way, here's our list of plug-in hybrids that will be on sale in the U.S. for the 2014 model year.
2014 BMW i3 concept live photos, 2011 Frankfurt Auto ShowEnlarge Photo
2014 BMW i3 ReX
New to the market early next year will be BMW's first plug-in electric car, an all-new dedicated vehicle that comes as a battery-electric vehicle or with a small two-cylinder range-extending engine.
The car's 21- or 22-kWh lithium-ion battery pack sits in an aluminum chassis structure, with a carbon-fiber reinforced plastic body shell on top. The shell is so strong that BMW can dispense with center door pillars altogether: the rear doors are rear-hinged, meaning the entire side of the car opens up for unparalleled ease of access.
A 125-kW (168 -hp) electric motor powers the rear wheels, but the "ReX" range-extended version uses a small two-cylinder engine and generator that also tucks under the rear deck.
That engine, along with a 2- or 3-gallon gas tank up front, will give the BMW i3 ReX almost double the battery range of 80 to 100 miles (figures haven't yet been released).
But, unlike the Chevy Volt and Cadillac ELR, performance in range-extending mode may not match that delivered by the battery pack.
BMW points out that the range extender is not meant for everyday use, but more for occasional and emergency situations.
The first BMW i3s are likely to arrive at dealers shortly after January 1, at a price similar to that of a well-equipped 3-Series, or perhaps $42,000 to $46,000.
The ReX range extender, however, will likely cost a few thousand dollars more on top of that.
2014 Cadillac ELR revealed at 2013 Detroit Auto ShowEnlarge Photo
2014 Cadillac ELR
The striking Cadillac ELR range-extended electric coupe has had a checkered history, with production approved and then canceled during the days of GM's 2009 bankruptcy.
Widely lauded for its striking lines, the production version of the ELR goes on sale later this year in a form remarkably close to the concept car shown in 2009.
It shares the Voltec range-extended powertrain of the Chevy Volt, including a 16-kWh lithium-ion battery pack housed in the tunnel and under the rear seat, and a 1.4-liter range-extending four-cylinder engine up front.
But the ELR is expected to have quite different electronic control software, giving it a different feel and most likely more performance to offset the weight of its many luxury features.
GM hasn't released final power, performance, range, or fuel-efficiency ratings for the 2014 ELR, nor has it said anything about its price.
That information will likely arrive this fall.