Red Bull and Toro Rosso are set for a boost in Canada as Formula 1 engine supplier Renault confirms reliability upgrades will be ready for this weekend's race in Montreal.
On the back of a frustrating start to the campaign, where both teams have been forced to run through their engine allocations, Renault has been working flat out on solving its problems.
Amid confidence that the French car manufacturer has now found a solution to its main issue, thanks to revised piston design, Renault is introducing the tweaks this weekend.
Renault F1 chief Cyril Abiteboul told Motorsport.com: "We had one particular issue which has been holding us back in terms of performance development, and we had to address that issue first."
The new parts will be run from Friday practice – in the engines that were used in Monaco – and then a decision will be made on whether or not to stick with that power unit for the rest of the weekend or switch to a fifth power unit.
Should it choose to change engine, then it will mean a grid penalty for its drivers.
The long straights that allow overtaking, high-chance of a safety car, and mixed weather in Canada, mean that grid position is not so important as it was in Monaco.
That is why Renault may even choose to tactically introduce a fifth engine, as starting further down the order is not such a handicap.
Abiteboul said: "It might be a bit calculated not because we cannot use the fourth engine any more but because we elect to use the fifth engine and maybe we will revert back to the fourth.
"Unfortunately now it is a bit of damage limitation from a sporting perspective. So we have to factor that into our engine allocation plan and deal with it."
Performance step delayed until Spa
Renault's focus on curing its reliability problems means that performance steps have had to be put on the back burner.
Should the new specification cure the piston trouble and allow drivers to run proper race mileage, then work can again ramp up on delivering more horsepower later in the campaign.
Abiteboul has suggested that Renault's teams can expect a step forward from the Belgian Grand Prix when it is likely to use its first in-season development tokens.
"When you deal with such a reliability crisis like the one we have had since the start of the season, you don't deal with anything else," he said.
"If you are working on that, you are not working on something else. So it has delayed the introduction of the performance that we know is available.
"In terms of performance upgrades, there will still be some over the season, but unfortunately the reliability crisis means they have been shifted from before the summer break to right after the summer break. But there is a plan."