Asked if the top end of the grid will be as close in Montreal as it was in Monaco, Briton Hamilton said on Thursday: "I'd be guessing but I don't feel that will be the case.
"Renault and Ferrari would have to have done an exceptional job coming into this weekend to be able to keep up with us on the straights," he added.
Indeed, Mercedes' rivals like world champion Sebastian Vettel (Red Bull) and Fernando Alonso (Ferrari) on Thursday conceded that Mercedes' advantage will surely be even more out of reach as the turbo V6s push significantly past 300kph.
Vettel said he cannot think of a more one-sided year without going back several decades.
"No one was as dominant since 1988," the German, referring to McLaren's memorable fight between Ayrton Senna and Alain Prost, is quoted by Speed Week.
"The gap is very big," said Vettel.
That is why there is so much attention at present on the inter-Mercedes relationship between warring teammates Hamilton and championship leader Nico Rosberg.
"For sure it would be good for us and everyone else on the grid if they take each other out," admitted Vettel, "but I don't think it will happen.
"They are both smarter than that," said the German.
"You should not be at war with your teammate as it hurts the atmosphere in the team. But you don't have to be best friends," added Vettel, who in the past years had a fraught relationship with former teammate Mark Webber.
Looking at the Hamilton versus Rosberg head-to-head for Montreal, it would appear that the smart money is on the Briton to reclaim the title lead this weekend.
Rosberg won the last two Monaco grands prix, but in Montreal he has never finished higher than P5.
Hamilton, on the other hand, has won at the Circuit Gilles Villeneuve no fewer than three times.
Rosberg said: "For me, he (Hamilton) is not the favourite. I'm here to win."
As far as Alonso is concerned, F1 should at least be grateful that Hamilton and Rosberg are at loggerheads.
"Their rivalry is good for the media," he is quoted by La Gazzetta dello Sport, "because this year the races are not too exciting with a Mercedes that dominates so much."