Red Bull Team Principal Christian Horner believes his team will have a better indication of how much progress they've made in recent weeks at next week's Canadian Grand Prix.
Red Bull and in particular Daniel Ricciardo just about matched Mercedes during last week's Monaco Grand Prix, even though the characteristics of the Monte Carlo street circuit negated the performance advantage the Merc power units have over their Renault counterparts.
Montreal's Circuit Gilles-Villeneuve is a completely different prospect to Monaco, though, and has several high-speed sections that will play into Mercedes' hands.
"Montreal is going to be a challenging race for us and it will be interesting to see how we fare there," Horner told crash.net.
"Obviously Renault are working hard behind the scenes.
"We were much, much closer, it was the first time we've raced Mercedes this year [in Monaco] and Dan's pace; particularly in the last third of the race he was the quickest car on the track. So I think we take a lot of confidence out of that.
"But you go from one extreme to the other. [Monaco] is all about handling characteristics and the next event will be predominantly straight-line performance. So it's going to be very interesting to see how we fare against Mercedes-powered teams in Montreal."
Even though Horner expects the Mercedes-powered cars to set the pace in Canada, Horner remains confident that Red Bull will continue to close the gap to the Constructors' Championship leaders as the season progresses.
"We're clearly the second-quickest team at the moment and we're nibbling in to that gap of Mercedes. It's nothing short of commitment, hard work and clever design that is going to close that gap.