BMW working on i5/i7 based on 5-Series platform?

BMW is reportedly pushing forward with development of its next i-Series model, likely named the i5 or i7, to serve as a direct rival to the Tesla Model S.
Referred to internally by the monicker F18, the plug-in hybrid vehicle is expected to be based on a long-wheelbase version of the next-generation 5-Series platform, unnamed sources have told Car.

The external design is said to blend elements of the existing 6-Series Gran Coupe and the next-generation 7-Series sedan, though the aesthetics have yet to be finalized.

The powertrain is reportedly adapted from the i8, pairing batteries with an internal-combustion range extender. Separate electric motors are expected to deliver 204 horsepower to the front wheels and 95 ponies to the rear, while the four-cylinder engine would produce around 245 horsepower. Electric-only operation is said to be good for 80 miles.

The company’s plans for third i-Series model have been the subject of several seemingly contradictory rumors. Previous reports have suggested that the i5 will actually be a Prius-style hatchback, or all-electric with a 200-mile range, or even hydrogen powered.

If the latest report proves accurate, the i5 or i7 could be revealed as early as September at the Frankfurt auto show.