Racing turns its back on heavy, expensive hybrids for sustainable fuel

Over the past decade, spurred on by series like Formula 1 and the World Endurance Championship, the world of motorsport began to embrace hybrid powertrains. In addition to being a sport and entertainment, racing also serves as a testbed for new vehicle technologies, having pioneered innovations we now take for granted, like seat belts, windshield wipers, and rearview mirrors. But that dalliance with electrification may be nearing its end as two high-profile series announce they're ditching batteries and electric motors starting next year in favor of sustainable fuels instead.

Formula 1 first officially allowed hybrid power in 2009, and by 2014, the series' rules required every car to sport a pair of complex and costly energy-recovery systems. The more road-relevant discipline of sports prototypes also began dabbling with electrified powertrains around the same time, with the first win for a hybrid car at Le Mans coming in 2012.

The budgets involved for those programs were extravagant, though. Until it instituted a cost cap, F1 team budgets stretched to hundreds of millions of dollars a year. In endurance racing, Audi and Porsche spent comparable amounts on their hybrid WEC campaigns, and while Toyota managed to make do with much less, even it was spending more than $80 million a year in the mid-2010s.

As the technology has matured, it made its way into other series—in 2022, both the World Rally Championship and the British Touring Car Championship adopted standardized hybrid systems with spec components that each team had to use. North America's IMSA WeatherTech series followed suit in 2023 by introducing the new GTP class—cars built to the LMDh regulations similarly use spec batteries, transmissions, and electric motor/generator units.

But the addition of hybrid systems in those series had more to do with making it socially acceptable for automakers to participate in them rather than with any great improvement to the racing. Indeed, at the 2023 Rolex 24 at Daytona, team principals told me for a fact that automakers like Acura and Cadillac would never have greenlit their IMSA prototype programs were it not for the hybrid aspect.

First BTCC

Until now, it seems. At the end of October, the BTCC announced that starting in 2025, it will no longer use hybrid power. "The hybrid era was a great one for the BTCC. Six years ago, when we first announced hybrid, it was a technology still in its relative infancy within motorsport. We've successfully completed that program—and really have no more to prove in that respect—whilst others have yet to catch up," said Alan Gow, BTCC's chief executive.

Instead of using a small electric motor to add 60 hp (45 kW) for short boosts, the BTCC will instead look to the cars' turbochargers for the extra power. Losing the electric motor and battery pack also sheds 122 lbs (55 kg) in weight, which means 2025-spec BTCC cars should be more nimble and no less fast. And the cost for teams should be lower—until now, teams have been required to lease the hybrid systems for tens of thousands of dollars a year.

Instead, the BTCC will require all competitors to use a new fossil-free fuel called Hiperflo ECO102 R100, made by Haltermann Carless with a mix of synthetic and biological sources.

Then WRC

The WRC's announcement that it will also delete hybrid powertrains from its technical regulations came last Friday. Here, too, the motivation was to reduce costs, complexity, and weight, cutting 176 lbs (80 kg) from the mass of a Rally1 car. (Power will be cut slightly via a smaller air restrictor for the internal combustion engine to keep performance at the same level as today's WRC cars.)

"Following extensive dialogue with key stakeholders, it became clear that continuing to use the plug-in hybrid units provided under the existing supplier agreement was no longer in the best interests of the FIA World Rally Championship," said FI Chief Technical and Safety Officer Xavier Mestelan-Pinon.

Like the BTCC, the WRC will instead move to a fully sustainable fuel—again, likely from Haltermann Carless, which currently supplies the series with its control fuel.

Could F1 follow?

As Ars has reported, F1 is also adopting carbon-neutral fuels from 2026, although unlike the more cost-conscious WRC and BTCC series, in F1 teams will be allowed to work with the fuel supplier of their choice as a way to spur more technology development. To coincide with the new sustainable fuels, F1 cars are losing the expensive and complicated energy recovery system fitted to the cars' turbochargers, instead opting to make the electric motor that can harvest and deploy energy to the wheels more powerful.

Critics of the current F1 technical regulations won't find much solace from the 2026 regs, which only look set to cut about 66 lbs (30 kg) of mass—as a result, the cars will still be much longer and heavier than the lithe and nimble machines that raced until 2013.

That incoming ruleset will last until 2029, but earlier this year, F1 CEO Stefano Domenicali revealed that the adoption of sustainable fuels could mean the end of turbocharged hybrid V6s from 2030. After all, if the fuel the cars burn doesn't contribute to climate change, there's no harm at all in their engines going back to naturally aspirated units with stratospheric rev limits and a screaming soundtrack to match. Here's hoping.