Honda has spent its first development tokens of the season to introduce a new turbocharger for the McLaren's of Jenson Button and Fernando Alonso for the Canadian Grand Prix.
Following a similar upgrade selected by Ferrari for Montreal, the Japanese manufacturer sees the high-speed and long straights as the ideal place to bring in the update after running extensive testing during the winter and in last month's in-season tests at Circuit de Catalunya.
With both Button and Alonso looking to maintain the team's upwards momentum with results, the Montreal circuit will be a tough examination on the Honda power unit and whether it has made sufficient gains against its rivals.
With Ferrari also upgrading its turbo for Canada, both manufacturers have spent two development tokens each. Ferrari will have four tokens remaining while Honda will still have 12 after opting not to spend any before Canada.
Renault, who spent three for Monaco with its engine upgrade, will introduce the new power unit configuration to Max Verstappen's Red Bull and Jolyon Palmer's Renault after their respective team-mates received the update at the Principality. Renault still has 14 development tokens remaining.
Mercedes will not introduce any upgrades for Canada and hold on to 11 tokens.