SOCHI, Russia -- McLaren will switch from Renault engines to Mercedes in 2021 after signing a new contract that will extend until 2024.
McLaren became a Renault engine customer after an acrimonious split with former works supplier Honda at the end of 2017. Since then, it has improved its form and currently lies fourth in the constructors' standings, ahead of the works Renault team but still some way off the top three teams Mercedes, Red Bull and Ferrari.
Although Ferrari has had the most powerful engine of late, Mercedes has won every championship since the introduction of the current turbo-hybrid formula in 2014 and looks set to win the title again this year.
For McLaren, the deal sees a return to the same engine supplier that helped the team secure its last four titles in 1998, 1999, 2007 and 2008 -- albeit then as a works team and not a customer.
"This agreement is an important step in our long-term plan to return to success in Formula One," McLaren CEO Zak Brown said. "Mercedes is the benchmark, both as a team and a power unit, so it is natural we would seek to secure a relationship with the company for the next phase of our journey.
"This announcement reflects the confidence of our shareholders and is an important message to our investors, employees, partners and fans that we are committed to returning McLaren to the front of the field."
The McLaren switch means Mercedes is expected to supply three customers on top of its works team from 2021, with Williams and Racing Point also using Mercedes power. Renault will be left with just its works team using its engines.
"Since our partnership began, McLaren has gone from ninth to fourth position in the Constructors' Championship," Renault team boss Cyril Abiteboul said. "We can therefore consider this a very successful relationship. However, while looking beyond the terms of the current contract, which concludes at the end of 2020, it was apparent that Renault and McLaren have different ambitions for the future.
"Each of the different elements of this decision have been carefully evaluated over the past few weeks. 2021 will be a crucial season for all teams and it is important for us to have a precise and clear view of the strengths and ambitions of our competitors going forward.
"This decision is in line with Renault's vision to become a works' team, with a goal to return to the front. Renault will continue to honour its commitments to McLaren Racing next season, as has always been the case over our long history of engine supply." Mercedes supplied three customer teams between 2014 and 2016 -- when the Manor outfit was still in F1 -- and will need to be granted special dispensation from the FIA to do so again, which is believed to be a formality at this stage.
Mercedes' engine department in Brixworth stands to benefit from a higher rate of learning by having eight cars running its engines at each race from 2021 and there is the potential for a strategic political alliance among the Mercedes team and its engine customers within the sport.
"We are delighted to welcome McLaren back to the Mercedes-Benz racing family with this new power unit supply agreement," Mercedes boss Toto Wolff said. "Although the two brands share a prestigious history, this new agreement is all about looking to the future and beginning a new era of power unit supply for the years ahead.
"McLaren have been putting in place the building blocks of their revival over recent seasons, including impressive performances this season with Renault power. We hope that this new long-term agreement marks another milestone for McLaren as they aim to take the fight to the sport's top teams, including our Mercedes works team."