How the Renault and Honda engines compare to each other in Montreal next week could determine Red Bull Racing's 2019 power unit choice.
Renault's Cyril Abiteboul has been asking the Milton Keynes-based outfit for clarity sooner rather than later on its future engine plans, but team boss Christian Horner insists Red Bull will continue to weigh its options until the end of June or early July.
"It will be a month or so. End of June, beginning of July. It's the time-frame we've always talked about," said Horner.
"We want to compare the two engines in Canada," added Horner, amid reports both Renault and Honda are planning upgraded units for the seventh round of the world championship.
"We'll get small updates in Montreal but we need to get the most out of them. It's very important to us."
Renault's power unit has reduced its deficit to its Mercedes and Ferrari rivals, but the French manufacturer has still not offered its customers the compelling qualifying modes enjoyed by its main competitors and necessary to fight for pole.
Horner believes that's the only thing keeping Red Bull from consistently challenging for race wins.
"If I'm not mistaken, in the last six races the five fastest laps were ours," he said.
"If we get more power in the last qualifying session, there will be nothing stopping us from making the lives of Mercedes and Ferrari very difficult."
Gallery: The beautiful wives and girlfriends of F1 drivers
Keep up to date with all the F1 news via Facebook and Twitter
Once again, a sensational Kimi Antonelli delivered when it mattered in Saturday’s Monaco Grand Prix…
Charles Leclerc cut a dejected figure after qualifying for the Monaco Grand Prix, with the…
Lewis Hamilton admitted that a sudden and unexplained change in Ferrari’s behaviour between Friday and…
George Russell struggled to explain his underperformance relative to Mercedes teammate Kimi Antonelli after a…
Saturday's qualifying at the Monaco GP will go down as one of the most tense…
Kimi Antonelli delivered a sensational late lap to secure pole position for the 2026 Monaco…