New & Used BMW i8: In Depth
2015 BMW i8, 2013 Frankfurt Auto ShowEnlarge Photo
The BMW i8 is a new type of high-performance, high-priced coupe from the Bavarian producer of the “ultimate driving machine”. It promises to not only be fast and offer impressive handling, but also to be exceptionally fuel-efficient—in the right circumstances, of course. Continuing after the i3, the i8 is the second model in the “i” lineup of BMW plug-in cars.
But the i8 coupe will likely cost twice as much as the i3, perhaps more, and it appeals to a different audience--those who want fast performance in a light car without the bulk and fuel consumption of a V-8 or V-10 engine fitted with multiple turbochargers.
First unveiled as the Vision EfficientDynamics concept car at the 2009 Frankfurt Motor Show, the i8 sports coupe is fitted with two entirely separate powertrains. Up front, an electric motor draws energy from a battery pack to drive the front wheels; a turbocharged 1.5-liter three-cylinder engine powers the rear wheels.
Two years later, the car had evolved into the BMW i8 Concept, which appeared at the 2011 Frankfurt Motor Show. The company has also shown an i8 Concept Spyder, indicating that the i8 will be offered both as a fixed-roof coupe and an open-air convertible.
In the 2011 car, which is much closer to the production version, the original concept's diesel engine had been replaced by a gasoline engine. That is BMW's new 1.5-liter three-cylinder engine--which will also be used in the next generation of MINI Coopers, as well as in a new front-wheel-drive BMW model.
At lower speeds and in zero-emission urban areas, the i8 will run for up to 20 miles solely on electric power from a 7.2-kilowatt-hour lithium-ion battery pack located in the tunnel between the car's two seats. At higher speeds and for longer distances, the 220-hp engine produces torque of 220 lb-ft to drive the rear wheels.
For maximum acceleration and output, both powertrains can operate in concert, making the i8 an all-wheel-drive coupe that some have called a "supercar." In this mode, the i8 becomes what engineers call a "through-the-road" hybrid, meaning that each powertrain operates a different set of wheels. The powertrains are so closely linked that the electric motor is tuned to make up the power lost during the gasoline engine's gear changes.
It's a new and novel design for a sports coupe, and the BMW i8 carries styling to match its novelty. Its design language is similar to that of the 2014 BMW i3 urban electric car, an upright five-door hatchback that is powered for 80 to 100 miles by a battery pack built into the floor. But the i8 coupe is low, sleek, and sporty where the i3 is short, upright, and capacious. And if anything, the i8 coupe's rear "wings" give it a more alien appearance even than the two-tone i3.
Both cars are built in two parts: an aluminum platform holds the battery, electric motor, and other powertrain components, while a body shell made of carbon-fiber-reinforced plastic (CFRP) sits on top. The combination is light, durable, and cutting-edge, with BMW about to become the world's leading automaker in the use of carbon fiber in mass production. The total weight of the BMW i8 is expected to be about 3,000 pounds, perhaps slightly more.
The result is a light and fast coupe that BMW has said will accelerate from 0 to 62 mph in less than 5 seconds, and reach a top speed of more than 150 mph. BMW hasn't released final specifications yet, but you can expect those sometime during 2014. The BMW i8 is likely to go on sale toward the end of that year as a 2015 model.