Viry-Châtillon, France - McLaren on Friday announced that it would drop Honda engines in favour of Renault at the end of this season, ending a troubled partnership with the Japanese manufacturer as the team bids to return to the top of Formula One.
The celebrated British marque announced a three-year deal covering 2018, 2019 and 2020 with France's Renault, who simultaneously unveiled a split with Toro Rosso - who will now be powered by Honda.
The related moves, which had been widely flagged, could ultimately herald a shake-up in the pecking order of Formula One, which is currently dominated by Mercedes and Ferrari.
Honda's exit is likely to convince two-time world champion Fernando Alonso, who has repeatedly threatened to quit over the misfiring Honda engines, to stay at McLaren next year.
"Today's announcement gives us the stability we need to move ahead with our chassis and technical programme for 2018 without any further hesitation," said McLaren executive director Zak Brown.
Britain's most successful Formula One team has failed to win a race since 2012 and is a long way from challenging Mercedes, Ferrari or Red Bull.
The vexed collaboration with Honda came to a head this month in Italy as Alonso and Stoffel Vandoorne both collected grid penalties and failed to finish.
Vandoorne was penalised before the race after being fitted with a brand-new engine - and still suffered a power failure.
Sainz to Renault, Palmer out
In the first ‘musical seats’ move of the 2017/2018 silly season, Renault also announced that Carlos Sainz would replace Jolyon Palmer for the 2018 season, alongside Nico Hulkenberg - although both Renault Sport Racing managing director Cyril Abiteboul and Red Bull’s Helmut Marko described the move as ‘a loan’.
Sainz, 23, has started 53 Grands Prix since his F1 debut in 2015 in Australia and has scored 100 points, with a best finish of sixth, achieved four times.
Renault Sport Racing made no mention of Palmer in its release, beyond wishing him well in the next steps in his career, so it’s safe to assume that those steps will not be with Renault.