Meeting of minds How best to build your EV
Do electric cars need bespoke platforms or can combustion engines share the same hardware? VW’s Frank Bekemeier and PSA’s Vincent Blessing argue their corners
Decisions made years ago are now coming home to roost. At one extreme, VW has bet the farm on building millions of electric cars on EV-only platforms. PSA, to the contrary, has committed itself to platforms that can be fitted with petrol, diesel, hybrid or full-electric powertrains. How did they arrive at these very different positions… and are they having any regrets?
Frank Bekemeier: VW’s vision from the beginning was that the MEB platform has to offer affordable electric vehicles for less than €30,000 (£27,000) in volumes of up to 10 million a year. The flexible architecture allows a wheelbase from 2750mm to 2900mm and wheel tracks around 1900mm for a wide range of models. We can also offer several battery packs. Without the ICE and ancillaries like the exhaust system, prop shaft and fuel tank there are fewer constraints for the designers, giving us the opportunity to develop features that are not possible in ICE cars, as well as freeing up interior space.
Vincent Blessing: The main advantage for PSA is for the brands to be able to propose the same vehicle with different powertrains. The other big advantage is the industrial one: we can use the same production line and people, globally, and use the same manufacturing plants and not a dedicated factory. Finally, the more you mitigate the investment the more you reduce the manufacturing costs and the price to the consumer.
FB: Rather than a compromise we saw it as an opportunity, because all the cars will be built using the same technological concepts. We had huge discussions with all our brands to ensure the cars are built the same way with the same technologies, although there are some adaptations from brand to brand. It means the tooling and production processes are the same.
VB: The challenge is to assemble, weld and paint on the same production line, so we have the same assembly time between EVs and ICE. It takes only about five more minutes to manufac
ture an EV than an ICE, because there are so many screws holding the battery pack to the underbody. That’s not automated for cost reasons; we’re working on eliminating that time difference.
FB: It really was a clean-sheet exercise to create the best concept for an e-vehicle. We get more interior space and a more modern, contemporary design than we could with an ICE.
VB: Look under the bonnet and there’s no synergy between an EV and an ICE – the architecture is all new for the EV. There’s a new powertrain mounting bracket and crossbeam for crash safety. Housing the battery pack under the floor was quite complex because we use the same underbody housing as the ICE version, resulting in less than 10mm additional ground clearance for the EV over the ICE.
FB: Of course the battery has more weight and the crash element might be more severe under impact so we have to protect it. We’ve done that by developing a special housing which, in itself, is part of the car’s architecture so the impact is absorbed without any deformation. Depending on which part of the structure they’re used in, we employ a combination of highstrength steels, hot-stamp steels and some aluminium to get minimum weight for the load paths.
VB: There’s 300kg weight increase because of the batteries and that’s a lot in a crash – more than 30 per cent more energy than in an ICE to dissipate. We switched the engine cradle from aluminium to steel and integrated crash beams that guide the forces through the cradle and under the bulkhead to prevent intrusion into the passenger compartment. It’s very hard to achieve the same NCAP figures for an ICE with an EV.
FB: Within the VW Group we had regular concept meetings with all the brands and they will bring their own unique interpretation to the cars, to prevent this ‘Russian Doll’ syndrome. They are the ones who have to manage that, because we know from past experiences with former platform developments that it might be a trap for us.
VB: PSA’s platform strategy has been working for more than 20 years, so I don’t think we have this syndrome.
We build very different vehicles on the same platforms with different wheelbases, wheel sizes and body styles ranging from saloons to SUVs. It’s a challenge for the designers to hide the common hard points.
‘It takes five more minutes to manufacture an EV than an ICE, because of all the screws’