Following successful tests at its Brixworth engine HQ, Mercedes has given Force India, Williams and its own works team an engine mode boost in time for this weekend's Azerbaijan Grand Prix.

With engines limited to just three over the course of entire 21-race season, it is understandable that the manufacturers don't want to take any risks in terms of reliability. However, successful tests at Brixworth has allowed Mercedes to give the green light to the three teams it supplies to run their higher engine modes for longer.

One of the first to appear to benefit on a circuit that witnesses some of the highest speeds of the season was Force India.

"Mercedes sometimes, rightfully so, will restrict the more potent modes that we run to a limited amount of time or laps," said Force India COO, Otmar Szafnauer.

"That's because of the way they go about developing," he continued. "They will validate from a reliability standpoint those modes to a point where they think that they're safe to run, and then they let us all run those. Then they'll go back during the season and have an increase on those modes, so you can run a higher mode for longer, and then they will stick that on the dyno and validate to make sure the engine will hold. When they are happy, then they increase the modes. And they've done that here."

Asked how much this might be worth, he revealed: "A tenth, maybe half-a-tenth in qualifying.

"It's a bit of a longer qualifying mode," he continued. "During the race, we run two modes. The race-plus mode as we call it. Everyone calls it something different. The quicker race mode, we can run it longer now. They increased it by a significant amount of kilometres, maybe 20 to 30km longer. It's lap time at the end of the day."

Check out our Saturday gallery from Baku, here.