Driving the BMW i8, the world's most advanced car

How does it work?

More than any other new vehicle, the BMW i8 requires this explanation up front — not just for the dull process of turning energy to motion, but for the whole enterprise of a $135,700 supercar designed for maximum eco appeal with styling from the 23rd century. And last week, I was among the first to find out.

In BMW engineer speak, the 2015 i8 is properly called a “plug-in electric hybrid sports car” — one with a 129-hp electric motor driving the front wheels and a turbocharged,1.5-liter three-cylinder engine with 228 hp driving the rear axle. Since I last drove a prototype of the i8 in August, some fine-tuning of the all-important software and electrical power unit has been done by the Munich madhatters, but the i8 remains the giddy thrill and conversation piece it was then.

I can already sense the comments that 357 hp and 420 lb-ft of torque for a $137,000 car is, like, a complete rip-off, man. That someone can buy two Ford Mustang Shelby GT500s for the price, blow an i8 away when the light turns green, and put the rest in a bank account. I wish them peace and happiness with this, but pure speed isn’t the point of the i8, although it can hustle to 60 mph in 4.2 seconds or less when set up in Sport mode.

The i8 looks like no other car, and its complex drivetrain (with two transmissions, a lithium-ion battery pack and more software than the starship Enterprise) leaves us grasping for comparisons. Up in the hills and pushing it hard, the i8 did pretty damned well in upholding BMW’s ancient mantra of “ultimate driving machine.” As I rolled along around the wealthier provinces of Southern California, I eventually came to one that made some sense. In overall performance and feel, I kept coming up with the smaller and lighter 321-hp Porsche Cayman S — though the Cayman S is dynamically the superior car and rather dramatically less fuel efficient depending on how I drive it.

While the front e-motor gets a two-speed transmission – first gear good up to 75 miles per hour, second on up to the 155-mph maximum – the rear gas engine gets a six-speed automatic you can leave to shift by itself or which you can shift manually via the console lever (only in Sport) or by using the steering wheel paddles. Once I got all the various new drive rhythms of the i8 imbedded in my subconscious and inner ear, the play time up and down the gears was entertaining. Both the electro-mechanical steering and adaptive dampers of the suspension are outstanding.

But there were a couple of refinement issues for me (and for other testers) on these launch cars that caused healthy conversation. The first one was the less than seamless transitions when going from the 129-hp front-wheel-drive eDrive to the all-wheel-drive 357-hp parallel hybrid mode in either Comfort or Sport. There is a slight feel of driveline shunt every so often, and I mean slight, but enough of it to make me wrinkle my nose whenever it happens. Between the software, the central electric brain, and a secondary 15-hp e-motor attached to the rear engine to in part help with these transitions, every so often an order or two gets missed.

Then, when a wheel happens to leave the pavement over a bump while in motion in the all-wheel-drive parallel hybrid state, the brakes blip on the axle with the momentarily lifted wheel. The subsequent resumption of normal all-wheel motion after all rubber re-meets the road can be less than smooth. The BMW engineer in charge tells me that the near full arrest of rotation on the one axle is done as a safety measure, in order to protect the drivetrain against the possibility of the lifted wheel or wheels spinning freely and risking damage to the system, since there’s no mechanical link between front and rear. Again, this needs a little tweaking, and I was assured that the software changes will carry on once i8 deliveries begin.

In straightforward momentum and handling, the i8 takes your sports car thrills to a different level. One of the more serious bits to decide was what tires to use, since the i8 needs to be a thrilling driving machine and not an extremely suped-up Honda Insight. BMW i has elected to give journalists the wider and less tall optional set of 20-inch tires to test – 215/45 front and 235/40 rear. These Bridgestone Potenzas do a good job overall, even while promising less rolling resistance and, in theory, less lateral grip.