Mercedes has revealed that its recent gearbox problems were a result of overly aggressive seamless shift settings.

Lewis Hamilton and Valtteri Bottas each incurred a five-place grid penalty during the last two rounds for prematurely taking new gearboxes, prompting the team to use a ‘safe spec’ in the most recent round at Silverstone.

Mercedes technical director James Allison admitted that the team had pushed its units too hard in order to eke time out of its gear shifts.

“In the old days, you’d be in a gear, then you’d be out of a gear and then you’d be in another gear and you’d just lose drive all the time that the gears were in transit from one to the other,” he explained.

“In a seamless shift, you are in one gear and then the next one takes over instantly, so there isn’t a loss of drive.

“But seamless though it is, there is still an amount of spinning stuff that needs to be slowed down to meet the next gear.

“The harsh (way to do that) is just letting rip. I can say this because it’s not a sort of thing that no-one else has thought of, it’s a standard thing in F1.

“It’s just a question of how bold you are with it.”

While Mercedes has a thorough reliability sign off when it comes to development, Allison says the team was caught out by real world factors such as g-forces which cannot be simulated on dynos.

“We have a process for signing off any new strategy or any new design and that process is actually quite cautious from an engineering point of view,” he said.

“We try to put it on the track as much as we can, but the opportunities for track running in a risk-free way are limited.

“So we have dynamometers back in the factory where we can create a fairly good representation of reality.

“We did all of our normal process to prove off a layer of greater aggression with the shift settings than we had used previously.

“But, despite the fact that everything looked fine in our sign off process, sadly that particular plan didn’t survive contact with the enemy on the track, where things were a little different, where the g-loads moved the oil around the box differently than you can simulate in a dynamometer.

“So we just overstepped the mark by the tiniest of margins and paid a price.”

Mercedes boss Toto Wolff admitted that the added pressure from Ferrari in 2017 has forced Mercedes to push even harder to find performance gains.

“It is probably better for the sport and for the entertainment factor that Ferrari is part of the mix now, but we are pushing so hard,” he said.

“And by pushing and trying to keep the development curve steep, you get setbacks.

“Headrests that become undone, gearboxes that break because you try to extract the last bit of bits that normally have no performance relevance any more, or not a lot. But they do.”

Wolff said another area that allows for small, but ultimately significant gains to be found, comes from fuel and lubricants supplier Petronas.

“For me, it is amazing that there are fluids you can extract performance from that I didn’t even know were in the car,” he said.

“And it adds up. You can find five milliseconds on a cooling product, you can find 15 milliseconds on a hydraulic oil.

“With the formula of oils and fuels and the density, you can extract so much more performance out of all these crucial parts of the internal combustion engine.

“The gearbox is another good example. Running the right oil in the gearbox can give you a performance advantage, it can give you a weight advantage, it can allow you to race more aggressively in terms of gearshifts.

“And sometimes as a team you get over-confident.

“That has happened to us on the gearbox. We’ve probably run it too hard and when we stuck the nose in after Baku we realised.”