Five years in development, this new hybrid super coupe goes on sale next summer for about $155,000. We caught up with a barely disguised preproduction model at BMW's proving ground in the South of France.
On-Sale Date: July 2014
Base Price (est.): $155,000
Competitors: Tesla Model S, Porsche 918 Spyder, Ferrari La Ferrari, Volkswagen XL-1, McLaren P1.
Powertrain: Turbocharged 1.5-liter I-3, 228 hp, 236 lb-ft; AC electric motor, 129 hp, 184 lb-ft; six-speed automatic (gas engine) with two-speed automatic (electric motor); AWD
EPA Fuel Economy (combined, est.): 94 mpge
What's New: With a far-out body wrapped around the carbon-fiber body tub, front and rear aluminum subframes, and a wishbone suspension at all four corners, the i8 mimics race-car build technology. But there the similarity ends. At the rear is a three-cylinder version of BMW's latest gas engines. It's turbocharged, with variable valve timing, double overhead camshafts, and four valves per cylinder, and drives the rear wheels via an Aisin six-speed automatic transmission. A 13-hp 74 lb-ft starter/generator adds to an already hefty amount of pep. Moving forward in the car, a large central tunnel backbone houses the fuel tank and the 220-pound 7.1-kilowatt-hour lithium-ion battery pack. Then, between the front wheels sits the i8's main electric motor that drives the front wheels via a GKN-made two-speed transmission.
The main difference between the heavy-duty tech in the i8 and the super-eco exotics we're expecting from McLaren, Ferrari, and Porsche next year is the BMW's lack of a drive motor at the rear wheels. And actually, the i8's performance is modest in comparison, with a top speed of 155 mph and 0-to-62 mph acceleration in 4.5 seconds.
Built alongside BMW's EV, the i3, in Leipzig, Germany, the i8 is brisk but economical. Carsten Breitfeld, head of the i Project, claims that even if owners never bothered actually plugging in, the real-world fuel consumption in the i8 would still be about twice as good as that from the M3. BMW expects to see 94 mpg (U.S.) in the NEDC (New European Drive Cycle) test. Recharge time on a 13-amp European domestic supply is about 2 hours.
Tech Tidbit: Readers with long memories will remember the torrid production dramas of two-speed transmissions in the first Tesla Roadsters. Transmissions for battery drivelines are tricky technology. As long as you restrict the top speed, an electric motor is almost flexible enough to use a single-speed reduction gear, plus its phenomenal low-end torque is tough on gears. BMW realized, however, that if it was going to specify a 155-mph top speed, the i8's electric half would require a transmission or else the acceleration would be that of a striking slug.
The GKN-manufactured gearbox sits below and behind the front electric motor. Its first-gear ratio of 1:11 is right at the limit of dry-road traction for the front wheels. Transmission software will keep the car in that ratio all the way to 75 mph (the limit of electric-only drive), whereupon it changes up and the motor and engine together will power the car to its top speed.
Driving Character: We don't know why BMW bothered with the interior disguise panels, as underneath them is a very conventional BMW fascia—apart from the doors, that is. These carbon-fiber-framed, aluminum-skinned doors hinge upward and forward from the windscreen pillars. They look terrific but are going to make tight parking a hit-or-miss affair, and those wearing skirts are going to have to find new ways to get into a car while retaining their modesty.
As for the cabin, it's classy, comfortable, and clearly laid out. There are, of course, additional instruments in the instrument cluster, such as the analog power indicator showing the electric motor input/output and a battery-state-of-charge meter. There is also a hold-charge function for when you need to preserve electric-only range for the end of a trip. The gear lever is entirely conventional, with a Drive and Sport position just as in current BMW cars, and the steering wheel has shift paddles behind it which rotate with the rim. The front seats are supportive, but some taller drivers found it difficult to get comfortable. We didn't even try to gain access to the vestigial rear seats, which are little more than parcel shelves. Still, the Porsche 911 has got away with this sort of rear accommodation for almost 50 years now. And besides, with a tiny trunk (5.44 cubic feet) in the rear behind the engine under a tilting hatchback, you'll value any extra space in the i8.
Press the starter and a polyphonic whoosh fills the cabin. Unless you stand on it, the i8 will almost always pull away in electric mode with a polite whirr and whine. There are four major drive settings. E mode uses only the front electric motor and the 5 kWh available from the battery for up to 22 miles and a 75-mph top speed. Unless you select the hold-charge button, the system will empty the battery to about 30 percent at first, then juggle gasoline and volts to maintain it at around that charge state. Comfort is the startup mode, where both power units are deployed in the interests of maximum efficiency. Sport uses both power units at full boost, with the little electric starter/generator helping the engine to scamper up to full boost in the interests of performance. There's also BMW's familiar EcoPro setting, which dulls the performance, selects high gears as much as possible and reduces the air conditioning setting to a feeble dribble. If you are driving south of the Mason–Dixon line forget about this mode.
So what does the i8 feel like? Kind of boring in front-drive electric mode, actually. The electrically powered steering settings are notch, but since this is designed for putting around city centers, we don't mind. The motor whines a bit, yet the main impression is of pretty supple suspension settings, reasonable ride comfort, and being in something rather special. Switch to comfort and the experience improves. The three-cylinder rear mill doesn't have the most charismatic of idle notes, but spools up well, with a deep muscular note partly engineered by BMW's sound engineers. The concept car we drove felt way short of the claimed 4.5-second 0-to-62 mph performance, but the handling of the low-slung coupe is terrific. Intentional slides happen with all four wheels, and the cornering attitude is adjustable with the throttle. Best of all, at no time do you feel a mismatch between the volt-powered front and gas-powered rear. BMW's engineers have done a bang-up job here, and there are conventional sporty BMWs that are not as fun as this.
Favorite Detail: I know I should cite the driveline here, but the thing that really stuck with me was the amazing side and rear windows, made of Gorilla Glass, which is chemically treated flexible glass that is laminated in three layers, virtually unbreakable, highly flexible, and acoustically quiet. It's the same sort of stuff they use in a smartphone.
Driver's Grievance: A couple of things, both of which BMW says it is working on. The first is a tendency to understeer just after turning into a corner. In fact, BMW claims the front motor should help to nix this tendency. The other niggle was the difference between the feeling of the major controls in all-electric mode, where it is an electric front-drive hatchback and feels as dull as that sounds, and when it is in Sport mode, where it feels like an all-wheel-drive thoroughbred BMW and is terrific fun. These settings need to be a little closer for our tastes.
Base Price (est.): $155,000
Competitors: Tesla Model S, Porsche 918 Spyder, Ferrari La Ferrari, Volkswagen XL-1, McLaren P1.
Powertrain: Turbocharged 1.5-liter I-3, 228 hp, 236 lb-ft; AC electric motor, 129 hp, 184 lb-ft; six-speed automatic (gas engine) with two-speed automatic (electric motor); AWD
EPA Fuel Economy (combined, est.): 94 mpge
What's New: With a far-out body wrapped around the carbon-fiber body tub, front and rear aluminum subframes, and a wishbone suspension at all four corners, the i8 mimics race-car build technology. But there the similarity ends. At the rear is a three-cylinder version of BMW's latest gas engines. It's turbocharged, with variable valve timing, double overhead camshafts, and four valves per cylinder, and drives the rear wheels via an Aisin six-speed automatic transmission. A 13-hp 74 lb-ft starter/generator adds to an already hefty amount of pep. Moving forward in the car, a large central tunnel backbone houses the fuel tank and the 220-pound 7.1-kilowatt-hour lithium-ion battery pack. Then, between the front wheels sits the i8's main electric motor that drives the front wheels via a GKN-made two-speed transmission.
The main difference between the heavy-duty tech in the i8 and the super-eco exotics we're expecting from McLaren, Ferrari, and Porsche next year is the BMW's lack of a drive motor at the rear wheels. And actually, the i8's performance is modest in comparison, with a top speed of 155 mph and 0-to-62 mph acceleration in 4.5 seconds.
Built alongside BMW's EV, the i3, in Leipzig, Germany, the i8 is brisk but economical. Carsten Breitfeld, head of the i Project, claims that even if owners never bothered actually plugging in, the real-world fuel consumption in the i8 would still be about twice as good as that from the M3. BMW expects to see 94 mpg (U.S.) in the NEDC (New European Drive Cycle) test. Recharge time on a 13-amp European domestic supply is about 2 hours.
The GKN-manufactured gearbox sits below and behind the front electric motor. Its first-gear ratio of 1:11 is right at the limit of dry-road traction for the front wheels. Transmission software will keep the car in that ratio all the way to 75 mph (the limit of electric-only drive), whereupon it changes up and the motor and engine together will power the car to its top speed.
Driving Character: We don't know why BMW bothered with the interior disguise panels, as underneath them is a very conventional BMW fascia—apart from the doors, that is. These carbon-fiber-framed, aluminum-skinned doors hinge upward and forward from the windscreen pillars. They look terrific but are going to make tight parking a hit-or-miss affair, and those wearing skirts are going to have to find new ways to get into a car while retaining their modesty.
As for the cabin, it's classy, comfortable, and clearly laid out. There are, of course, additional instruments in the instrument cluster, such as the analog power indicator showing the electric motor input/output and a battery-state-of-charge meter. There is also a hold-charge function for when you need to preserve electric-only range for the end of a trip. The gear lever is entirely conventional, with a Drive and Sport position just as in current BMW cars, and the steering wheel has shift paddles behind it which rotate with the rim. The front seats are supportive, but some taller drivers found it difficult to get comfortable. We didn't even try to gain access to the vestigial rear seats, which are little more than parcel shelves. Still, the Porsche 911 has got away with this sort of rear accommodation for almost 50 years now. And besides, with a tiny trunk (5.44 cubic feet) in the rear behind the engine under a tilting hatchback, you'll value any extra space in the i8.
Press the starter and a polyphonic whoosh fills the cabin. Unless you stand on it, the i8 will almost always pull away in electric mode with a polite whirr and whine. There are four major drive settings. E mode uses only the front electric motor and the 5 kWh available from the battery for up to 22 miles and a 75-mph top speed. Unless you select the hold-charge button, the system will empty the battery to about 30 percent at first, then juggle gasoline and volts to maintain it at around that charge state. Comfort is the startup mode, where both power units are deployed in the interests of maximum efficiency. Sport uses both power units at full boost, with the little electric starter/generator helping the engine to scamper up to full boost in the interests of performance. There's also BMW's familiar EcoPro setting, which dulls the performance, selects high gears as much as possible and reduces the air conditioning setting to a feeble dribble. If you are driving south of the Mason–Dixon line forget about this mode.
So what does the i8 feel like? Kind of boring in front-drive electric mode, actually. The electrically powered steering settings are notch, but since this is designed for putting around city centers, we don't mind. The motor whines a bit, yet the main impression is of pretty supple suspension settings, reasonable ride comfort, and being in something rather special. Switch to comfort and the experience improves. The three-cylinder rear mill doesn't have the most charismatic of idle notes, but spools up well, with a deep muscular note partly engineered by BMW's sound engineers. The concept car we drove felt way short of the claimed 4.5-second 0-to-62 mph performance, but the handling of the low-slung coupe is terrific. Intentional slides happen with all four wheels, and the cornering attitude is adjustable with the throttle. Best of all, at no time do you feel a mismatch between the volt-powered front and gas-powered rear. BMW's engineers have done a bang-up job here, and there are conventional sporty BMWs that are not as fun as this.
Favorite Detail: I know I should cite the driveline here, but the thing that really stuck with me was the amazing side and rear windows, made of Gorilla Glass, which is chemically treated flexible glass that is laminated in three layers, virtually unbreakable, highly flexible, and acoustically quiet. It's the same sort of stuff they use in a smartphone.
Driver's Grievance: A couple of things, both of which BMW says it is working on. The first is a tendency to understeer just after turning into a corner. In fact, BMW claims the front motor should help to nix this tendency. The other niggle was the difference between the feeling of the major controls in all-electric mode, where it is an electric front-drive hatchback and feels as dull as that sounds, and when it is in Sport mode, where it feels like an all-wheel-drive thoroughbred BMW and is terrific fun. These settings need to be a little closer for our tastes.
Bottom Line: Viewed from the last decade, the i8 might look like much ado about nothing. A 3284-pound sports coupe capable of 155 mph, 0-to-62 mph in 4.5 seconds, and who cares about the gas mileage. For the next decade's sensibilities, however, the i8 might be the way all sports cars will start to look. The i8 is the best of both worlds: pricey, exclusive, desirable, and gorgeous to look at, but not as wallet-warpingly nuts as the rivals from McLaren, Ferrari, and Porsche. What's more, BMW, under fire in China for less-than-stellar environmental credentials and a humiliating 5 Series steering recall, needs something to convince the Chinese that they are serious about the environment, not just treating the country's new rich as gullible cash cows. The current quick-charge/deplete hybrid battery is the only hurdle to boosting the front motor by another 30 hp, so we should expect that a quicker i8 is in the works and, because the carbon roof panel is a nonstructural cover, a convertible version won't be that far away, either.
It could be that BMW has hit a sweet spot of price, economy, and environmental performance with the i8. Silicon Valley types should start forming an orderly queue.
It could be that BMW has hit a sweet spot of price, economy, and environmental performance with the i8. Silicon Valley types should start forming an orderly queue.
No comments:
Post a Comment