MOTORSPORT NEWS - The Canadian Grand Prix could determine whether Red Bull decide to stick with Renault, who powered them to all their Formula One championships, or switch to Honda engines from next season.
Team boss Christian Horner said after Sunday's Monaco Grand Prix, won by his Australian driver Daniel Ricciardo, that a decision would have to be made by "end of June, beginning of July".
"We're waiting with great interest to see the relative performance of engines in Montreal in two weeks' time," he added.
Canada, on 10 June, is the seventh round of the 21-race season and both manufacturers are planning to bring major upgrades to the Circuit Gilles Villeneuve.
Red Bull, whose Renault engines are branded Tag Heuer, have won twice this season but have had a rocky relationship with the French company since the start of the V6 turbo hybrid era in 2014.
Honda are working with Red Bull-owned Toro Rosso and have improved the performance of their engine notably since the termination of a three-year partnership with McLaren.
While Ricciardo is third overall in the championship, he has suffered reliability problems -- as well as a costly crash with teammate Max Verstappen -- and is 38 points off Mercedes' leader Lewis Hamilton.
The Australian is out of contract at the end of the season and is also waiting to see what engine Red Bull go for.
