BMW is heavily rumoured to be releasing an electric version of its X5 SUV which should be called the BMW i5. Now an official comment suggests this model will come with a Range Extender option.

Head of product for BMW, Henrik Wenders, commented to Car and Driver on the company's next i model electric vehicle: "We are thinking of a new i model above it to attract families, and that means it must be capable of being the first car in the household."

The family comment adds weight to the larger SUV style vehicle like an X5, only dubbed an i5. To help make that transition while still maintaining range Wenders pointed out that BMW would use lightweight cabon-fibre for the i5, something the i3 already uses.

Wenders went on to comment on the Range Extender in the i5: "The range-extender plays an important part in the next years when range remains a limiting factor and a source of anxiety."

The Range Extender is a small two-cylinder engine that's used to enhance the distance a solely electric BMW can manage. On the BMW i3, for example, the full electric model is limited to 81 miles while the Range Extender version tops out at 150 miles.

Rather interestingly Wenders says that 60 per cent of i3 purchases were with Range Extenders but only 5 per cent of those people regularly use it. "Itr was purely a psychological thing," Wenders says.

Don't expect the BMW i5 to arrive before 2020.

READ: Mercedes-Benz E-Class 2016 first drive: The Einstein of luxury cars