The BMW i3 stands out among electric cars because it’s offered in both conventional all-electric form, and as an “REx” model with a small gasoline engine that acts as a range extender. Unlike the other popular range-extended electric car, the Chevy Volt, the i3 REx isn’t designed to run further on gasoline power than it can on electric power.
BMW i product manager Jose Guerrero offered some insight into why the company set the car up that way in a recent interview with BMW Blog. He said BMW intended the REx to be used like a standard battery-electric car, and not for drivers to lean on the gasoline engine too much. In a way, the REx is “almost like training wheels for the [i3] BEV,” he said.
Guerrero noted that BMW wanted the i3 to be an electric car first, meaning it wanted to ensure that drivers spent most of their time on electric power. A development requirement was that the gasoline range not vastly exceed electric range (the 2016 i3 REx has a rated 72 miles of electric range, and 150 miles on both electric and gasoline power). That differs from the Volt, which Guerrero somewhat dismissively compared to plug-in hybrids like BMW’s own X5 xDrive40e.
It’s worth noting that BMW didn’t just design the i3 REx to burnish its green credentials. The range-extended powertrain was also set up specifically to allow the i3 to qualify as a range-extended battery-electric vehicle or “BEVx” under California emissions rules. The i3 was the first production vehicle to qualify for that category, which places restrictions on the design of the range extender and how it can be used. Among other things, this allows the i3 REx to qualify for a $2,500 California tax credit.
The i3 is expected to get a range boost this year, although BMW has not discussed the details of that. Further into the future, Guerrero hinted that the electric car could become a platform for autonomous-driving technology, saying that said technology “is ready today.”