GKN Debuts Fully Integrated Electric Car Drive System In Shanghai

Time was when car companies made cars. They made the engines, transmissions, and axles. They made the sheet metal and the seats. Just about the only thing they didn’t make themselves was the windshield and the rest of the glass. Today, those companies are more assemblers than they are manufacturers, especially when it comes to electric and electrified cars. Someone else makes the electric motor. Someone else makes the battery. Another company makes the battery management system. GKN is one of the world’s largest OEM suppliers. Lately, most of its focus has been on building an electric car drive system that manufacturers can buy ready made and install at their own factories.

The advantage for car companies is they don’t have to spend precious resources to develop proprietary electric car propulsion systems. GKN has done all the R&D. All the manufacturer has to do is tell GKN how many units it wants and when. First presented publicly at the  Shanghai auto show, the GKN product is the first to use a fully integrated design that packages the electric motor, power inverter and eAxle reduction gearbox into a single housing. Putting all the pieces in one unit makes it easier for manufacturers to integrate the drive components into its vehicles.

Called the eDrive system, is about 15% smaller, 10% lighter, more efficient than electric car drive systems that use separate components. Building one product for several manufacturers means GKN can spread the cost of development over more units, which brings economies of scale into play and permits lower costs than conventional drive systems. Lower electric car prices are good for everyone, especially consumers.

The close proximity of the components results in significant improvements in both mechanical and electrical efficiency, GKN says. The optimized packaging also helps reduce noise and vibration. GKN designed in the necessary cooling from the start, leading to further efficiencies in the system.

China is expected to be a major electric car market and GKN expects its eDrive system to satisfy the needs of many Chinese manufacturers. It predicts that its Chinese joint venture — Shanghai GKN HUAYU Driveline Systems (SDS) — will produce over 1 million eDrive units per year by 2025. Peter Moelgg, CEO of GKN Driveline says: “We constantly work in partnership with our customers to make our technology smaller and lighter, while retaining high performance and efficiency. Our eDrive concept being presented in Shanghai is a perfect example of this, showcasing GKN’s expertise in complete mechanical and electrical systems that will enable the next-generation of electrified vehicles.”

GKN has a wealth of experience with electric drivetrains. Since 2002 and has produced nearly 400,000 eDrive units at its factories in Europe and Japan. The company was instrumental in the development of the powertrain for the Porsche 918 Spyder and the two speed eAxle in the BMW i8. It also supplies the eAxle used in the Volvo XC90 T8 Twin Engine plug-in hybrid.

Source: Electric Cars Report

GKN Driveline develops new e-drive system for PHEVs; starts production on global platform in 2019

GKN Driveline has developed a new, complete electric drive system for plug-in hybrid vehicles (PHEVs). The system will start production in 2019 on a global platform from a European vehicle manufacturer.

Tighter integration of electric drivelines improves system efficiency and gives automakers more packaging and assembly options. The new module integrates a water-cooled electric motor and inverter with a single speed eAxle reduction gearbox. The system generates a maximum 65 kW of power and can deliver up to 2,000 N·m (1,475 lb-ft) of torque to the rear wheels.

The complete eDrive module measures 300 mm high and 325 mm wide and weighs 54 kg (119 lbs), making it around 20 mm narrower and 2.5 kg (5.5 lbs) lighter than comparable systems. Despite significant differences in the acoustic signatures of the inverter, motor and gearbox, the overall system delivers a smooth, near silent electric driving experience.

This is the first all-in-one eDrive system to replace external wiring with a bus bar and to eliminate unnecessary mechanical interfaces. The result is an eDrive system with higher power density that is simpler to install.

—Peter Moelgg, Chief Executive of GKN Driveline’s eDrive and AWD business

GKN has been advancing the development of eAxle technology since 2002 and has produced more than 300,000 units at its manufacturing facilities in Europe and Japan. The company was awarded Official Porsche Technology Partner status for its contribution to the plug-in hybrid Porsche 918 Spyder program.

GKN launched the world’s first two-speed eAxle in the plug-in hybrid BMW i8 and also supplies the eAxle on the Volvo XC90 T8 Twin Engine PHEV program.

A new generation of vehicles is making hybridization integral to platform strategies. These complex drivelines require the higher levels of system integration that GKN eAxle electric drive modules deliver. By pioneering the development of these systems, GKN is positioned to help automakers turn electric propulsion into exciting new hybrid all-wheel drive experiences.

—GKN Driveline Chief Executive Phil Swash

BMW In A Quandary About Its Electric Car Future

The Paris auto show is coming up later this month, but the head honchos from BMW won’t be there. Instead, they will be huddled together, trying to figure out if it is possible to actually make a profit building and selling electric cars. BMW was one of the early leaders in the electric car game. Its innovative i3 turned plenty of heads with its carbon fiber structure and off beat styling. Its i8 plug-in hybrid sports car also got rave reviews.

But the problem with the world is that things never stand still for very long. Sales of BMW’s “i” cars have been disappointing, to say the least. The company has yet to turn a profit on them and the number of potential competitors has increased exponentially since the i3 first debuted. Upper management is at a loss to explain how Tesla convinced 400,000 people to plunk down $1,000 to reserve a Model 3 when it can’t find buyers for its electric car offerings.

For more than a year, we have heard conflicting rumors from BMW insiders about what the next “i” car will be. An electric 5 Series, perhaps? Or an SUV? Bigger? Smaller? More money? Less money? We have heard it will arrive anytime between 2018 and 2023. Clearly, there is confusion in the upper echelons of the company. Which is why BMW management will be skipping the Paris show this year so they can meet and come up with a coherent strategy for the future. That will be a welcome change.

The latest reports from BMWBlog and Reuters suggest that company leaders are deadlocked on a proposal to re-issue the electric MINI. Brand managers for MINI say it will cost too much to develop an electric version. Stuffing an electric powertrain into the existing MINI will require significant changes to the existing chassis — changes that will cost lots of money. The same goes for altering the i3 chassis to make it into a MINI.

Part of the problem is that for the past 25 years, BMW has led the automotive industry in profitability. Management is reluctant to forfeit that leadership position to build electric cars that make less money or are unprofitable altogether. BMW is not Tesla, which is willing to lose money today to make money in the future. It’s a problem for BMW, one that has no clear solution.

“How does the company expand into the loss-making segment of electric cars and retain its industry-leading profitability. That’s essentially the question facing management now,” a source inside the company reports. That is the problem with disruptors like Tesla. They aren’t concerned with the status quo or next quarter’s earnings report, but BMW management definitely is.

Part of the problem with being an old line, established company like BMW is that management tends to get top heavy with senior executives. Carsten Breitfeld, who headed the i3 project, has left the company to Future Mobility Corporation, a Chinese start-up. “I worked in BMW i for some years and we did some new things,” he told Reuters in China. “After doing this first step, BMW stepped back and waited for what would happen in the market.”

Breitfeld, who took several other former i division employees with him, says now he deals with maybe 10 other people. At BMW, more than 500 were involved and it took 6 months to a year to make a decision about anything.

The big powwow at the end of September is supposed to create an electric car strategy for the Bavarian car company, one that balances innovation, costs, and profitability. In a sense, BMW is one of the dinosaur, legacy companies that Tesla Motors is trying to shake out of their complacency and lethargy. Its painful for those who are used to being on top to be pushed around by the new kids on the block.

But that is the essence of the capitalist model, which tears down old companies on one hand so new, more efficient enterprises can take their place. It may seem impossible to think of a world without BMW in it, but if the company’s managers don’t figure out how to adapt to the inevitable changes coming to the marketplace, that’s precisely what could happen.

Rumor: All Electric BMW i8 In Development

Klaus Fröhlich, head of development at BMW, tells Autocar that the firm’s i division is working on a prototype that could lead the way to an all electric BMW i8 in the near future. At the heart of the prototype are three high revving but compact electric motors — two in the rear and one in front.

“Revs are the route to making electric motors smaller,” sources within the company say. “BMW has a great history of high-revving combustion engines. We’re looking to take this tradition into the electric car arena with electric motors that rev far higher than those seen in production today.” The proposal to build the prototype is said to be on Froehlich’s desk, awaiting approval.

The prototype will be based on the carbon fiber structure developed for the i division’s fuel cell concept car. In order to make room for the hydrogen storage tanks, it had a wider center tunnel than the production car. “The idea is to use the space within the widened center tunnel to house the battery instead of the hydrogen tanks,” the source says.

Even with the larger battery, ditching the internal combustion engine means the electric car will weigh the same as the current i8 at 3,274 pounds. Range is projected to be 249 miles in the European test cycle, which is considerably more optimistic than the US standard. That number would translate to about 185 miles in US numbers.

The production i8 has a total of 357 horsepower on tap. Autocar’s source says the new brushless motors may be capable of spinning out 268 horsepwer — each!

BMW is working on a revised i8 that incorporates many of the upgrades used in the safety car it provides for the Formula E racing series. The improvements include a larger 26 kWh battery borrowed from the X5 xDrive40e. The onboard wireless charging system from QualComm operates at 7.2 kW instead of the 3.6 kW power level in use previously. Reports are that the updated car will get a 10% increase in total power, a rumor that BMW refuses to confirm. The refreshed i8 is expected to go on sale next year.

Source: Autocar    Photo credit: Autoblog

BMW i Car Engineering Team Decamps For China

Most of the top engineers who developed the BMW i3 and i8 have left the company and joined yet another new Chinese electric car start-up. This one is called Future Mobility Corporation and is backed by Tencent Holdings. Carsten Breitfeld, a 20 year company veteran who was responsible for crafting the i8 plug-in hybrid sports car, left BMW last month.

Breitfeld will become the new CEO of Future Mobility and will be joined by three other senior members of BMW’s i division — Dirk Abendroth, who developed electric powertrains for the i-series; Benoit Jacob, who was head of design at BMW i; and Henrik Wenders, head of BMW i product management.

Their defection comes as BMW struggles to move its i division forward. The i3 was ground breaking when it was first introduced in 2011, but it has remained relatively unchanged since then. The i3 is in line for a larger battery and the i8 reportedly will go topless soon as well, but those developments are small potatoes compared to the blockbuster news coming from Tesla on a regular basis.

Rumors about a third product for the i division are rampant, but senior company officials say whatever it is, it won’t come to market before 2020. “That’s too long for young people who want to change the world,” a person close to the company tells The Wall Street Journal. It is believed Breitfeld and the others simply got bored waiting for the company to figure out where it wants to go next with the i division.

Sales of the i3 and i8 totaled almost 30,000 cars last year. That’s less than the number of Model S sedans Tesla Motors delivered. With Tesla claiming it will be selling 300,000 or more cars annually it the very near future, there is a sense that BMW lacks a clear vision for how it plans to move forward into the electric car future.

BMW i8: Jaw-dropping style and green performance, but why?

Why is there a BMW i8? Given the relative simplicity, affordability, practicality and energy efficiency of BMW's i3 sedan – available as a $42,000 all-electric or $46,000 extended-range EV – why design, engineer and build the much more complex and expensive ($137,450) but much less practical, exotic plug-in hybrid i8 2+2 sports car?

In 2015, BMW sold 2,265 i8s in the US, or about 189 a month. That compares to 11,024 (919 a month) for BMW's own i3, an estimated 27,840 (2,320 a month) for Tesla's battery-only EV Model S sedan and 1,024 (85 a month) for Cadillac's handsome, more practical and less expensive (but ridiculously overpriced and dismal-selling) ELR extended-range-EV luxury coupe. Are such sales really worth BMW's huge investment of engineering effort and dollars?

The i8's lightweight Carbon Fiber Reinforced Plastic (CFRP) "Life Module" passenger cell rides on an aluminum "Drive Module" chassis that houses its complex propulsion system – a 228-horsepower, 1.5-liter turbocharged gas 3-cylinder (half of BMW's 3.0-liter twin-turbo straight six) driving its rear wheels through a six-speed automatic and a 129-hp electric motor twisting its front wheels through a "two-stage" automatic – and a 5-kWh lithium-ion battery. Its drag coefficient (Cd) is an aero-slick 0.26, and BMW says it can run on battery energy alone for up to 22 miles.

Its total system output is a healthy 337 horses, and its EPA economy is 76 miles per gallon equivalent in gas-electric mode, but just 28 mpg when it's gas-only. A Driver Experience Control and an eDrive button offer EV and Comfort modes, plus Eco Pro (12 percent more range) and Eco Pro+ (12 more).

So what is this gorgeous plug-in hybrid sports car like to drive and live with? I missed its press launch so have been hoping for some quality time with one ever since. Production has been limited, and US press cars are few, but BMW said I would eventually get my chance. It finally happened.

If the unlovely i3 is a green technology revelation, this supermodel-sexy i8 is a green styling and performance revolution. If the i3 is the practical soccer mom of battery BMWs, the i8 might be the ultimate Teutonic trophy wife. But really, why do it?

For starters, just look at it. Some might see a new, high-tech take on the Giugiaro-designed BMW M1 mid-engine sports car. Just 453 of those were built from 1979 to 1981. But this low-riding rolling sculpture has so much more going on: swept-back nose with chrome-ringed kidneys flanked by squinty, LED-framed headlamps; sweeping rocker sculpting; flying-buttress raised rear roof; lightweight doors that open upward and outward like a bird's wings.

Duck under the bird-wing doors, bend over, sit on the seat's edge, curl your legs, swing them inside. Not easy, but rewarding.

Duck under those bird-wing doors, bend over, sit on the seat's edge, curl up your legs and swing them inside. Not easy, but ultimately rewarding. And well-placed door-pulls help. Lay your hands and eyes on the lovely steering wheel and surprisingly user-friendly controls and instruments. Most will be familiar to BMW drivers, though some are i8-specific, and all are bathed in cool blue light at night. Getting out can be even more challenging. Watch your head. And its vestigial rear seats are near-useless except to extend its barely-there storage capacity.

We drove it to dinner. Nearly everywhere it goes, nearly everyone double-takes and points. "What is that?" My car-loving wife was duly impressed by its looks but less by its challenging ingress and egress. Surprisingly, probably remembering its mostly freeway delivery drive the day before, its EV range gauge offered just 10 battery-only miles.

I found only one 12V outlet for my radar detector, under a cover in the very shallow bin atop the console. But plugging anything into it blocks the cover from closing, and the open cover protrudes into passenger space. The outlet proved powerless anyway (probably a blown fuse), so I would have to risk driving the i8 sans protection from (traffic ticket) revenuers.



On the up side, the wedgy i8 looked fabulous snuggled between parked SUVs at the restaurant, and it was fun watching people react to it. If we had chosen a fancier place with valet parking, it would have been posed proudly out front amid an array of big-ticket rides.

The dinner trip, plus two other stops, totaled 13.2 miles. We started EV Only, but the engine joined in after 8.3 miles of easy local driving. We arrived home with 387 miles of gas/electric range remaining and 41.4 mpg on the economy gauge.

Following an overnight plug-in, the i8's indicated EV range was up to 16 miles and total range to 403. I took it to a nearby Home Depot and back (not for siding or lumber), using 12 miles of EV range in 10.9 miles of Eco Pro+ EV-Only local driving. My trip fuel efficiency was an indicated 99.9 mpg (no gas burned) and my average economy was up to 45.7 mpg.

Even without a functioning revenuer detector, I had to give it an aggressive test, and it came through with typical BMW flying colors. There's no Sport mode, but its performance was exhilarating, its steering crisp, its handling planted and its braking sure and strong. It may be a fine-looking eco machine in normal driving, but it's an exotic AWD sports car on twisty roads.

But why do it? Mostly because BMW can.

I was truly sorry to see the i8 depart after a week of fuel-thrifty high living with it, and it delivered an impressive 47.3 MPGe average fuel economy in my week of local usage. Major kudos to BMW not just for doing it but for doing it so beautifully right. But why do it?

Mostly because BMW can. Because such a production machine (unlike a one-off concept) is an indisputable rolling demonstration of its technology chops. Because its increasingly sophisticated state-of-the-art technologies will be rolled into future hybrids and electrics, most of them both more affordable and practical. Since both British marques are owned by BMW, these technologies will likely also migrate upward into Rolls Royce hybrids and MINI EVs.

For the same reasons Ferrari, McLaren, and Porsche have engineered and built hybrid supercars, and why Cadillac will likely try again. There are even rumors that the long-rumored mid-engine Chevy Corvette, which should appear fairly soon, may offer a hybrid or electric version. Because such high-dollar exotic green vehicles are all about reputation and image, leading to long-term sales success, rather than their own near-term sales and profitability.

BMW X5 Plug-in Hybrid Comes w/ i8 Tech Baked In

The BMW i8 is a stunningly beautiful plug-in hybrid with wicked acceleration. But it was also a lab where BMW introduced some innovative technology to use in future vehicles. BMW i8 eDrive technology offers superb drive quality (or as the video below points out, “exceptionally efficient performance”) with all-electric driving and zero tailpipe emissions when the battery is juiced- but the company needs more than a single sports car to survive. Enter: the BMW X5 hybrid, the company’s first plug-in hybrid SUV.

BMW explains in the video, above, that it only makes one thing, “the ultimate driving machine.” The eDrive technology found in the BMW i8 is now available in the BMW X5 with eDrive, a plug-in hybrid SUV that’s about to hit the market and is “greener than a Prius.”

Described as “a beauty of a vehicle with a target fuel economy average (gas + electric) of 62 mpg (3.8 liters per 100 kilometers), about 18 miles of electric range, and able to do 0-60 in under 7 seconds” in this previous EVObsession post, many are excited about this upcoming electric SUV and its BMW i8 roots … which got us thinking: having both an i8 and an X5 xDrive probably wouldn’t be too bad of a situation to find yourself in, you know?

BMW's Ominous Black i8 Fuel-Cell Prototype: What It Sounds Like - VIDEO

Very, very few people on the planet have ever seen a car powered by hydrogenfuel cells, much less ridden in or driven one.

But if you've wondered what they sound like in operation, now's your chance.

At a recent technology presentation, BMW showed off two different prototype vehicles powered by hydrogen fuel cells, part of its technology partnership with Toyota on advanced powertrains.

Now a recent video on the YouTube channel Cars demonstrates what a fuel-cell powered vehicle sounds like when it comes whooshing past you.

And given the mysterious, even ominous, flat-black paint on the heavily modified BMW i8 prototype car, the sounds somehow match: The vehicle sounds almost as unusual as it looks.

2016 Toyota Mirai hydrogen fuel-cell car, Newport Beach, CA, Nov 2014

As we learned from our drive in a pre-production 2016 Toyota Mirai hydrogen vehicle, the low-speed behavior is pretty similar to that of an electric car.

Both types of vehicles use powerful electric motors to turn the wheels; it's only the source of the electricity that's different.

At lower speeds, the Mirai sounds pretty much like a Prius hybrid in all-electric mode. Tire noise and a bit of background whine are the dominant sounds.

But at higher speeds, Toyota's hydrogen sedan adds a variety of additional noises as the compressors and pumps increase the volume of hydrogen fed to the fuel-cell stack to increase the power output.

BMW hydrogen fuel cell technology

The "whoosh" you hear in the BMW video is matched by a similar sound, though less pronounced, in the Mirai. It comes from water vapor being expelled out the tailpipe.

The Toyota also manifested a high-pitched whir (we called it a "wheeze") from the air compressor that feeds oxygen into the fuel-cell stack.

No hydrogen fuel-cell car will generate anything like the powertrain noise of a vehicle powered by an internal-combustion engine which, after all, is producing thousands of tiny explosions to move itself along the road.

But we rather like this video because it shows off the alien nature of hydrogen fuel-cell powerplants.

Electric cars are quiet, perhaps with a little whine; hydrogen fuel-cell cars add an element of different, almost otherworldly, audio to the experience.

BMW i8 Get Hydrogen Fuel Cell Drivetrain

While Elon Musk believes electric cars are the future, and Toyota maintains that hydrogen fuel cells are a better idea, BMW has committed to playing both angles. After the successful launch of the BMW i3 and i8, the German automaker has rolled out a hydrogen fuel cell concepts based on an early i8 test mule.

When it launched, the BMW i8 came with a 3-cylinder gas-powered engine pair with two electric motors driving the rear wheels, giving the plug-in hybrid about 23 miles of electric driving range and 357 combined horsepower. However, it still relies on gasoline once the 7.1 kWh battery pack is drained, and while the 76 MPGe rating is better than the hydrogen-powered Toyota Mirai, the i8 still ends up spewing emissions from its tailpipe.

That changes with the eDrive Hydrogen Fuel Cell prototype. BMW has toyed with hydrogen as a replacement for petrol in various ways, and while the hydrogen-powered BMW i8 appears to be the fruits of the BMW-Toyota tech-sharing alliance, it was actually built in 2012, before the alliance was ever cemented. With 300 miles of range per tank and a sinister look, the hydrogen-powered eDrive BMW i8 was actually one of the first test mules built before production.

But where the plug-in hybrid version of the i8 dolls out a combined 357 horsepower and can zip from 0 to 60 MPH in just 4.4 seconds, the hydrogen version of the i8 makes just 268 horsepower and takes 6 seconds to reach 60 MPH. BMW also fitted this experimental drivetrain to a 5 Series GT, and the rumored BMW i5 could offer both a plug-in hybrid and hydrogen drivetrain.
That said, given the above specs, I know which one I’d prefer.

• 

BMW i5 Could Arrive As Tesla Rival By 2018

Unlike many of its rivals, BMW decided to do its plug-in cars properly by developing standalone platforms for the i3 and i8. The result was the creation of two excellent plug-in cars, the i3 and i8, which have left positive impressions with consumers at opposite ends of the luxury car spectrum. The BMW i5 is slotted to fill the gap between the i3 and i8, and rumor has it that Bimmer’s Model S fighter could make its debut as early as 2018, rather than 2020 as earlier rumors suggested.

BMWBlog reports on a rumor from Germany’s AutoBild magazine puts the reveal date of the BMW i5 at sometime in 2018, underpinned by the extended-wheelbase version of the Chinese-market 5 Series sedan. Internet speculation has suggested that the i5 could get any of a number of different alt-fuel drivetrains, including a hydrogen fuel cell stack from technology partner Toyota. The two automakers are also working on a joint sports car project.

AutoBild’s information says the BMW i5 will be a plug-in hybrid using Bimmer’s new eDrive technology, combining a 218 horsepower gas engine with two electric motors. The motor at the front will make around 150 horsepower with a second motor at the rear good for 272 horsepower. When all three motors work together, total output is an exceptional 640 ponies, just 51 horsepower less than the mighty Tesla P85D.

But where the P85D can still travel over 250 miles on electricity alone, the BMW i5 will be limited to about 125 km/78 miles of EV range per charge. Even that’s likely a generous estimate at this early stage, as German automakers routinely game the fuel economy tests that result in optimistic ratings all but unreplicatable in the real world. BMW is targeting annual sales of about 30,000 units with a cost of about €100,000/$106,000, right around where the P85D is priced in America.

There’s also no doubt that Tesla will be updating the Model S in meaningful ways over the next three years, so by the time the i5 hits the market, who knows what Elon Musk might have already unveiled? Some of you might say “A plug-in hybrid isn’t an electric car rival!” but you’re looking at it the wrong way.

Instead, think about it like this. Tesla builds luxury cars that happen to be electric. BMW builds luxury cars across a much wider range of models and drivetrains. They’re still competing for the same buyers, the ones simply looking for an exciting-enough driving experience to drop a hundred-large on. Yes, there are buyers who ONLY want an all-electric car, but there are even more who still want the crutch of gasoline’s convenience.

Will the BMW i5 be the Tesla fighter many are hoping for? Or is BMW still a few generations behind Musk and Tesla Motors? Mark 2018 as they year we find out.

Image: AutoBild

BMW i8 Named World Green Car Of The Year

The auto industry has performed an amazing about-face in less than a decade, shifting its focus from gas-guzzling SUVs to fuel-sipping hybrids and gas-free electric vehicles. That has made earning accolades like the World Green Car of the Year all the more important, and this time around the winner is the BMW i8, making it the second consecutive win for BMW in this prestigious category.

Ulrich Kranz, Director BMW i Model Line said, “We feel extremely honored, receiving this prestigious World Green Car award for the BMW i8. Together with the 2014 World Green Car Award for the BMW i3 it just confirms the rightfulness of our purpose-built strategy when it comes to electric cars. BornElectric instead of conversion is the way to go.” Consumers seem to agree, as BMW has had to increase production of the i8 in order to keep up with demand and lower a growing waitlist of eager buyers.

The BMW i8 beat out a shortlist of nine other green cars. including the Mercedes-Bens S 500 Plug-In Hybrid and the Volkswagen Golf GTE. It also follows up the BMW i3, which won the Green Car of the Year last year, and is the third such award since 2010 when BMW’s BlueMotion diesel technology took home the prize. Five green car experts ultimately chose the i8 was the best representative of eco-friendly automotive progress in 2014, and it was just a few months ago that Top Gear dubbed the hybrid Bimmer their own Car of the Year.

The experts commented that, “The BMW i8 gasoline hybrid looks so cool, it should be the icon for all ‘Green’ cars..So it inspires Green Passion, which on paper looks like 155 mph on the i8’s three cylinder turbo gasoline engine, four-wheel-drive and four seats. The i8 adds so much enjoyment to a sensible lifestyle that it needs to be recognized as a great Green Car.”
Couldn’t have put it any better myself.

Hybrid Electric Corvette Design Study

What’s the hottest hybrid sports car: The Porsche 918 Spyder, the BMW i8?….and how much do they cost? In the case of the Porsche don’t even ask. You can’t afford it. The i8 is attainable for those that can afford to spend 100,000+ on a novel sports car.

But what about GM? We all know that the current Corvette offers a maximum bang for the buck in the performance department compared to the exotics. Could GM bring this same design philosophy to an electric hybrid version of the Corvette? If they did, what configuration would it be?

A Look at the Competition

It’s always good to know what you are up against. What are the details of the Porsche 918 Spyder and the BMW i8 power trains?

The 918 is an mid engine AWD with an electric front axle. The ICE is a V8 mounted lengthwise ahead of the rear transaxle. Sandwiched between the V8 and the transaxle is an electric motor. The transaxle gearbox is a conventional 7 speed. A battery sits cross wise in the car behind the driver’s seat. The front and rear inverters are separate units instead of integrated ones in the gen 2 Volt.

The i8 is also a mid engine AWD with an electric front axle. The 1.5 liter inline 3 is mounted transversely and mated to the tranaxle assembly resulting in a much more compact design than the Porsche. A belt-driven 20 horsepower motor generator is added in the rear to supply regen and to act as a starter motor. The transaxle gearbox is a conventional 6 speed. The battery runs down the tunnel of the car unlike the 918. The front electric axle incorporates a 2 speed gear box.

GM Design

One thing is clear when looking at the competition. They chose a mid engine AWD design. While some may think that the Corvette is traditionally a front engine RWD car, a mid engine design from GM is not without precedence. The father of the Corvette Zora Duntov was a big fan of mid engine AWD. In fact he designed more than 1 prototype. The most noted being the CERV II shown in figure 3.

Knowing what the competition is doing, what technology could GM leverage to improve on the i8 and 918 designs.

The first and simplest change is to integrate the inverters as GM has done in Gen 2 Volt. The i8 and the 918 use separate inverters.

The second improvement is to use an electric front axle utilizing a co axial gearbox as in the Spark EV. This results in a much more compact design.

The 3rd improvement is in the ICE. BMW is already talking about an M version of the i8 that uses a 4 cylinder instead of a 3 cylinder. GM should therefore just go with a turbo i4 with 2000 cc instead of a 1500 cc turbo 3 boosting power from 228 to 300 horsepower. In addition GM should mount the ICE transversely like the i8 for a more compact transaxle than the Porsche.

The 4th improvement is the biggy. Both i8 and Porsche are using conventional 6 and 7 speed gearboxes. Their transaxles are mostly ICE powered. The main electrical part is the front electric axle. This results in poor performance in EV mode. The i8 0-60 time in EV mode is only around 12 seconds.

GM should leverage Gen 2 Voltec technology in the rear transaxle assembly. This would give the electric corvette superior performance in EV mode over the i8. Existing gen 2 motors could be used. However the mechanicals such as shafts and gears would need to upgraded to handle the higher power output of the ICE.

The performance specs of the new AWD electric Corvette are presented in figure 6.

What is the first thing we notice in the comparison? The new Vette has a respectable 0-60 time in EV mode where the i8 does not. The Corvette has more AER. The new corvette will be a fundrive in EV mode. 4.9 seconds is just fine for everyday electric driving.

The next thing you notice is that the new Corvette blows the doors off the i8 when the ICE is on. The Corvette gets to 60 in 3.2 seconds compared to 4.5 for the i8. This is primarily a result of the whopping 557 combined horsepower when the ICE is on. In EV mode the Corvette still sports 320 horsepower compared to only 129 horsepower for the i8.

I’m sure Zora Duntov would be proud of this new AWD electric Corvette. It will provide superior performance to the i8 for tens of thousands of dollars less.

Source: GM-Volt