BMW's electric car lineup, the tiny i3 commuter and the i8 plug-in sports car, leaves a huge gap for a more practical, mainstream vehicle in between.

Rumors have circulated since shortly after the i3's debut that the company was working on a new model to fill the gap—a hatchback to be called the i5, sort of a BMW-esque Chevrolet Volt, or a long-range plug-in 3 Series GT.

Based on a teaser video the company released in a  Tweet ahead of the Beijing Auto Show, the rumored car may be on its way.

Since car-based "crossover" SUVs have captured the imaginations of buyers around the world since the i3's debut, the new car is now also considered part of BMW's X SUV lineup, and will be called the iX3.

It's not clear whether it has changed to a taller crossover format from a more traditional hatchback during its long development time or whether BMW always planned it as an SUV from the beginning and there were other delays. 

BMW Chairman Harald Krueger told BMW Blog that the iX3 would become the third car in the company's electric i lineup, and announced that it will go on sale in 2020.

BMW Vision Dynamics concept

BMW Vision Dynamics concept

The fourth model will be the BMW i4, based on the Vision Dynamics concept that the company showed in Geneva last year.

The iX3 is expected to be based on the current X3, though it may look significantly different.

Krueger said the car will be a fully-electric, though the i3 and i8 both have small gasoline "range extenders," and BMW has made plug-in hybrids a mainstay of its lineup in recent years with models such as the 330e, the 530e, and  X5 xDrive40e. 

It seems likely the iX3 may be available with a gasoline range extender as well.