Renault will travel to Montreal with an ungraded engine in its bags but the manufacturer has yet to decide who among its works drivers and customer teams gets the new unit.
Both Red Bull's Daniel Ricciardo and McLaren's Stoffel Vandoorne are on the penalty bubble following engine element failures earlier this year, while Fernando Alonso and Renault works drivers Carlos Sainz and Nico Hulkenberg still have a one-element margin before a grid drop kicks in.
"We have a new spec engine," Renault Sport F1 boss Cyril Abiteboul told Motorsport.com.
"We have yet to confirm the introduction, because the mileage is not the same across all cars, so we will see where and when exactly we will introduce that new spec.
"I think we have six engines available, subject to the last event on procurement in the supply chain.
"That's the plan, but not sure it's actually the best to introduce it in all six cars, in particular Red Bull.
"We need to look into that. We always work in partnership with teams, trying to do the best for the overall season result."
Abiteboul said the new-spec unit's gains will be marginal, slightly boosted by an updated internal combustion engine.
"It's a small gain in power, although we know we won't be the only one," said the Renault Sport F1 boss.
"It's mainly in the ICE that we can expect more power. This has to be the focus, and it will be the focus for all of this year, and maybe next year."
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