BMW’s long-awaited third-generation electric car won’t just be electric. The company announced last week that the upcoming i3 will be the first electric car from a mainstream automaker with an optional range-extending engine.

The i3, formerly known as the MegaCity concept vehicle, is an all-carbon-fiber electric city car planned as the successor to the Active-E, a 1 Series-based electric car that becomes available for select leasing this fall.

BMW did not announce what engine would be used as a range extender, but the automaker did say the engine will not be connected with the wheels. Instead, it will only serve as a generator to produce electricity for the electric motor once the batteries are depleted, much like how the Chevrolet Volt works.

The company says the battery in the all-electric version of the i3 will be good for 80 to 100 miles and that the top speed will be limited to 93 mph. As in the Active-E, the i3’s 170-hp electric motor will be mounted on the rear axle, driving the rear wheels. It is reportedly 40-percent smaller than the motor in the Mini-E.

The car will be about 151 inches long, 79 inches wide, and five feet tall, with a 101-inch wheelbase, making it a little shorter and wider than a Nissan Juke.

The company also previewed the other end of its upcoming electric car lineup, the i8. The i8 is a low-slung, all-wheel-drive plug-in hybrid sports car with a 129-hp electric motor powering the front wheels and a 220-hp, 1.5-liter three-cylinder gasoline engine driving the rear. Combined output is 349 hp, good for a blistering 0-60 mph run in less than 4.6 seconds, BMW claims. The i8 will have an all-electric range of 20 miles before the gas engine will have to kick in, though the engine can be tapped as needed for maximum performance. Charge time is said to be under an hour and a half. Like the i3, the i8 is also made of carbon fiber, and it weighs less than 3,300 pounds. BMW says the i8 is 182 inches long, 77 inches wide, and 50 inches tall, giving it supercar-like proportions.

The i3 and i8 are scheduled to debut in 2013. No price was announced.

Along with the i3 and i8, BMW also announced a new midrange model for its new electric car line, the i5. Using the same drivetrain as the i8, it is due out in 2016.

With fuel economy and emissions standards tightening around the world and the price of oil on the rise, even performance automakers are being forced to go green.