A new debate is raging among the world’s automotive companies, and it will likely take years to sort out. Its simple question: Should electric cars be constructed differently from combustion-engine cars?
Ulf Sudowe says yes.
The r&d director for chassis at Spanish supplier Gestamp Automoción gives the example of the time it tested an electric motor on the subframe of a standard Volkswagen Up minicar.
“Everything was destroyed,” Sudowe said. The ramp-up of torque for an electric motor happens so fast, he said, that a standard subframe couldn’t cope.
For the electric e-Up, Gestamp developed a unique subframe. But the difference between the two meant that new stamping dies were needed for the new subframe, increasing the costs and complexity of producing the electric version.
Volkswagen Group worked hard to avoid such complexity when creating its Modular Electric Toolkit, commonly known as MEB. The $7 billion investment is expected to enable VW Group to build everything from compact cars to large minivans using many of the same parts, providing the crucial economies of scale that the company says will enable it to make electric vehicles profitably.
VW will build MEB vehicles in eight locations globally starting in 2022, and the company predicts it will sell 15 million vehicles on the platform in the next decade.
But what if it doesn’t?
“If the EV demand isn’t there, Wolfsburg is going to have a big, big problem,” Max Warburton, an analyst at research and brokerage firm Sanford C. Bernstein, wrote in a report.
Other manufacturers have the same fears.
“If we predict the success of the 3 series, we are pretty much spot on,” Oliver Zipse, the new CEO of BMW Group, said just before his appointment was announced in July. “Predicting electromobility is much more difficult.”
BMW, Jaguar Land Rover and PSA Group have rejected VW’s solution of a stand-alone platform. Instead, they are creating flexible platforms that encompass combustion and electric drivetrains.
“In 2030, we might have a different approach,” Zipse acknowledged. “But we are not living in 2030, and we believe very firmly this is the right answer to keep the company afloat and profitable.”
By keeping platforms flexible, BMW can adjust production of a drivetrain based on demand, Zipse said. Factories can be easily adapted. “To integrate different drivetrains in one plant without losing efficiency, that’s the secret,” he said. “Either you can do that or you cannot. And we can do it.”
And customers won’t care, Zipse said.
“You will not feel any difference between a single-purpose platform, a conversion platform or a flexible architecture,” he said. “Maybe two kilograms here or there. But it’s not relevant for a buying decision.”
Not everyone agrees.
“In an ideal world, you would do everything on a bespoke platform,” said Tim Urquhart, principal automotive analyst at IHS Markit. “The whole point of an EV platform is that it doesn’t have to be too complex. You have the skateboard platform and have a blank canvas. It will afford you many more advantages.”
Simplifications to an EV-only platform might include dropping the brake calipers and drums on the rear axle because brake regeneration means they’re no longer needed, said Patricio Barbale, senior chassis analyst at IHS Markit. And using electric power to introduce more energy-hungry electric systems, such as steer-by-wire, saves space.
For the MEB platform, VW has switched to rear-wheel drive on the simpler versions, which means the instant power delivered won’t corrupt the steering. VW also emphasizes that its cabins will be larger because they can push farther forward into space that no longer contains an internal combustion engine.
“The length of a Golf, the room of a Passat” is how VW describes the first car on the MEB platform, the ID3, which was unveiled this month at the Frankfurt auto show and will go on sale next year.
An automaker that builds on a unique platform can market the car differently from a similar-size combustion-engine version of the model. That will be important given that — for a few years yet, anyway — the expense of the battery pack will price electric models higher. VW is already doing this.
“The Modular Electric Toolkit jettisons all the ballast of the fossil age,” VW declared in its marketing. MEB, it said, led to “fundamental” changes for everything from body design to interior packaging.
Meanwhile, an EV on a flexible platform could inspire unfavorable comparisons to its cheaper combustion-engine version.
But VW isn’t the only one investing in EV-only platforms. Daimler is working on the Electric Vehicle Architecture, or EVA2, which is expected to reach the market in 2021. Two sedans and two SUVs will likely use it first.
Meanwhile, Renault-Nissan-Mitsubishi is developing the CMA, an electric-only, flat-floor version of its broader Common Module Family architecture. It is expected in 2022. And in Japan, Toyota is working with Subaru on an EV-only platform it announced in June. No timing has been given.
EV-only platform designs with the batteries sandwiched in the floor present their own problems. The batteries raise the height of the floor, reducing rear foot space, as a quick test of the ID3’s rear seats at Frankfurt revealed. And in vehicles in which the battery box’s size pushes toward the edges of the structure, more crash protection is needed.
“In a side impact, you have a very limited zone of deformation to the battery — about half,” said Niclas Brännberg, director of computer-aided engineering for the Chinese EV brand Nio. That means extra stiffness, meaning more expensive extruded aluminum beams for Nio. But Brännberg, who previously worked for Volvo and Saab, estimates that the cost of developing an EV-only platform is similar to that of a combustion-engine platform.
VW is way ahead on cost with MEB, said Sudowe of Gestamp, which builds battery boxes and chassis parts for vehicles using that platform. “MEB will be the benchmark for everyone,” he said. “It’s very good on the price perspective.” For example, all MEB models except the minivan will use the same control arms, saving money on dies.
Sudowe estimated that MEB is around half the cost of the EV-only platform Jaguar Land Rover developed for the Jaguar I-Pace.
The I-Pace platform, designed as a halo car to beat Jaguar’s premium rivals to market, is not expected to be further developed. Instead JLR will migrate models to its new flexible Modular Longitudinal Architecture starting next year. The first model to use it will be an electric version of the XJ large sedan.
In some cases, suppliers are being asked to plan flexibility into their EV-specific parts, in case production volumes prove to be lower than forecast — or higher.
“Today, probably none of our customers are absolutely sure how fast the market is going to move to EVs,” Gestamp Executive Chairman Francisco Riberas told Automotive News Europe. VW recently doubled its order of battery boxes for MEB cars from Gestamp to 570,000 a year. The order indicates growing confidence that customers will switch to EVs as European laws tighten to combat carbon dioxide emission levels starting in 2020.
VW’s confidence is partly because it has the scale. That is increasing now that Ford Motor Co. has agreed to use VW’s MEB for a range of European electric cars. For automakers without the brand reach to spread the investment, a flexible platform makes more sense.
“They want to minimize the risk,” Riberas said. “Even if maybe a platform is not the best for EVs, they adapt it so they have a bit more flexibility in terms of volumes. It might not be the best solution, but it will probably be the most intelligent.”