Automaker is expected to introduce range of vehicles of new energy efficient i-sub-brand ahead of their Frankfurt show debut.

BMW has announced it will hold a press conference on Friday July 29 at noon, European time, to introduced the public to the new i-sub-brand.

The automaker offered few details beyond that but we can expect the i3 and i8 models to be part of the unveiling (ahead of the i-brand's full Frankfurt show debut) - either still in prototype form or in ready-to-go production guise. Perhaps BMW will use the occasion to make additional model announcements.

The i-sub-brand will feature the BMW logo with a blue ring around it to distinguish the new nameplate.

The i3 is an all-electric city car while the i8 will be highly-efficient hybrid with a petrol engine for global appeal.

Gallery: BMW will hold i-brand preview/press conference on Friday