Honda will return to Formula One as a full-blown engine manufacturer powering Aston Martin's title ambitions when the sport enters a new era in 2026, the Japanese carmaker announced on Wednesday.
The new 'works' partnership will transform Silverstone-based Aston Martin into Honda's sole focus on the starting grid from their current position as one of four teams with Mercedes engines.
"It is very, very difficult to win consistently championships without a full works relationship, which is why we've made this decision," Aston Martin's Group CEO of performance technologies Martin Whitmarsh told reporters.
Honda Racing Corporation (HRC) president Koji Watanabe confirmed the manufacturer had no plans to supply power units to other teams.
Honda officially withdrew from Formula One in 2021 but has continued to provide engines to reigning world champions Red Bull, who have already announced a deal with Ford from 2026, under a technical support arrangement.
CEO Toshihiro Mibe said the 2026 regulations and Formula One's push for sustainability were in line with Honda's carbon neutrality goals.
"The key for winning will be a compact, lightweight, and high-power electric motor with a high-performance battery capable of handling high and swift power output, as well as the energy management technology," he said.
"We believe that the technologies and know-how gained from this new challenge can potentially be applied directly to our future mass production electric vehicles, such as an electric flagship sports model, and electrification technologies in various areas."
Formula One's 2026 power unit will use 100 per cent sustainable fuels and have a much greater electrical component, with the sport aiming to be carbon neutral by 2030.
Silverstone-based Aston Martin are owned by Canadian billionaire Lawrence Stroll and are second in the championship after five of 22 races, with Spaniard Fernando Alonso taking four third places.
Stroll has invested heavily, building a new factory and wind tunnel and recruiting top staff from rival teams while also attracting significant title sponsorship from Cognizant and Saudi Aramco.
"Aston Martin Aramco Cognizant is building a team to win in Formula One," said former McLaren principal Whitmarsh, who was instrumental in bringing Honda back to that team in 2015 but left before the ill-fated partnership started.
"This is an extremely exciting and important further step for the team.
"It's clear to us and to Honda that the 2026 Formula One regulations will require the full integration of chassis and PU [power unit] that only a full works team relationship delivers.
"So to have this partnership puts us in a position to compete for championships."
Renault-owned Alpine, Audi, Ferrari, Mercedes-AMG High Performance Powertrains and Red Bull Ford will be the other engine manufacturers from 2026.
The break from Mercedes will mean Aston Martin having to build their own gearboxes and rear suspension but Whitmarsh said that was all part of "growing up" as a team and becoming truly independent.
"You set out to win in Formula One and that means beating existing partners and in order to do that we've got to be independent," he said.
"We're building great facilities and progressively pulling away from our dependence on Mercedes-Benz."
Whitmarsh said the team would continue to compete as Aston Martin after 2026.