Formula E now has its highest number of automaker teams to date with Porsche and Mercedes-Benz joining Nissan, Jaguar, Audi, BMW, DS, Nio and Mahindra in the motorsport championship that uses only battery-powered cars.
Automakers are attracted to the series, whose sixth season began Friday and runs until July 26, because it's a relatively cost-efficient way of marketing electric cars to viewers who mainly watch to see big-name drivers racing closely on tight street circuits.
However, the tight cost control that makes it appealing is now creating another dilemma. Formula E markets itself partly a showcase for technology that will find its way to future mass-produced EVs, but in some crucial areas it's starting to lag behind.
The series has made big strides since it first arrived in 2014. From season five, the batteries used by all the cars jumped in size to 52 kilowatt-hour from 28 KWh, which meant the drivers could complete an entire race without swapping cars halfway through.
However, Formula E has always played it safe.
EV entrepreneur Mate Rimac said he pushed organizers to make the series more technologically challenging with features such as battery swaps, torque vectoring and two motors in the rear that would have made the races more exciting for spectators.
"They probably made the right choice to make it simpler, reliable. I was not expecting it to be so reliable. But in terms in technology they could have been a lot more bold," he told Automotive News Europe.
Rimac, who has taken his electric sports car company from its start in a garage near Zagreb in his native Croatia, to a 400-employee business part-owned by Porsche, was involved in Formula E as an early sponsor but later pulled out.
Porsche's Taycan, its first full-electric car, highlights the technology gap that is opening up between road EVs and race cars. The Taycan has a peak charging capacity of 270 kW, one the fastest in EVs that are currently sold. However, all Formula E cars charge at a peak rate of 100 kW.
"Porsche can charge their road cars faster than their race car, so clearly as an industry we need to get the story straight," said Anthony Law, head of motorsport batteries for McLaren Applied Technologies. The company has supplied each of the teams with the 380 kg battery pack since season five.
Battery cells are another area where Formula E is perhaps not at the cutting edge of technology. The cylindrical cells, made by Japanese supplier Murata, are also used in power tools and were chosen more for their reliability than any specific breakthrough in energy density.
"We have benefited massively in the last season from the fact that the cells are being produced in high volumes and to extremely high quality," Law said. No car in the first season of using them stopped on track due to problems with the cells, he said.
Innovation in Formula E is partly stifled because aspects such as charging, the battery pack, the chassis and aerodynamic package come from single suppliers.
Standardizing these elements restricts the teams' ability to gain an edge on rivals but there are advantages in terms of cost control and unpredictable racing.
Dilbagh Gill, team principal of Mahindra Racing, said Formula E would become like Formula One if battery and chassis elements were not standardized.
Formula E might be hitting season six, but it's still too early to dilute the marketing message.
"We are still at a level that we need to talk about electric mobility rather than talking about a Mahindra or a Porsche electric car," Gill said.
Formula E is promoting the whole industry, he said.
"As a marketing tool Formula E is the really the only option at the moment," said Michael Caracamo, Nissan's global motorsport director. "You can see that by the number of manufacturers here."
It's not all standardized. The teams can use their own electric motor, inverter (which switches direct current electricity to alternating current) and gearbox. It's in this area, as well as the software they use, where teams can look for breakthroughs to give them both an edge on track and improve future electric road cars.
Jaguar gives the example of its use of silicon carbide in the inverter, where the material allows faster switching speeds than standard silicon.
"Now we can decide about the applicability for production cars but we know the proof point is there and it is beneficial," team principle James Barclay said. "Without Formula E we wouldn't have had that."
Managing the flow of energy through the drivetrain via software is one area teams agree is crucial. "Software is almost like the aerodynamics of Formula E," Barclay said.
The advantage is not more power. Teams are restricted to 200 kW (268 hp) from the engine, or 250 kW in qualifying. Instead it helps teams use battery power more efficiently.
"In Formula E it's not just about the fastest lap but how much energy did you consume to achieve that lap. And then how do you sustain it," Mahindra's Gill said.
In terms of efficiency, Formula E cars really are world leading.
Gill said the Mahindra car runs at about 95 percent efficiency, meaning 95 percent of energy is converted to power through the wheels, compared to 82 percent efficiency when the series started in 2014. That's compared to about 82 percent for road EVs, about 49 percent for Formula 1 engines and 36 percent for combustion engine road cars, according to Gill.
This efficiency achievement is being studied by Porsche road car engineers.
"Our road-car colleagues used partly use the Formula E laboratory to test new technologies and see how efficient we can go," said Pascal Zurlinden, Porsche's director of factory motorsport.
While EV road cars become more advanced with each new launch, Formula E will now see no big changes until the third-generation cars appear in the 2022/23 season. Already teams are in discussion with the series management team about which technology they can advance.
"For Generation Three you're going to see a lot more about charging," Gill said, predicting speeds of up to 600 kW. He also wants Formula E to spur venues into providing their own fast charging infrastructure, meaning the series can ditch the glycerin powered engines they install as chargers for each event. He also wonders if the charging speeds would allow teams to pit for a quick charge mid-race.
Other innovations could include using the front axle to recapture energy lost in braking and not just the rear, meaning the battery size and therefore weight could be reduced.
It's very important that the series is seen as cutting edge.
Said McLaren's Law: "We need to be showing Formula E is ahead of road-car technology pushing forward. We would hope to be showing in Generation Three that it's leading the way."