Sebastian Vettel has called on Ferrari to fix its Achilles heel, its transmission.

Having been handed a five-place gearbox penalty in Austria, where the German crashed out following his tyre failure, even though it wasn't damaged the team took advantage of the rules to give him a new unit for Silverstone without penalty.

However, following problems with the new gearbox on Friday, it failed again on Saturday morning, necessitating another unit and another 5-place grid penalty.

The German has had enough.

"The problems we had yesterday and today, that's a weakness and we need to stop it," the German told reporters following a qualifying session in which he finished sixth.

"I think, on the other occasions it was more a consequence of things happening, especially the first one, if you crash, and it was a mild crash, but still a little crash in China, we had to change it. But the issue we had yesterday and today is something new and we need to fix it.

Thankfully, there were no issues in qualifying, but the penalty still leaves the German starting from 11th.

"We took some precautions going into qualifying and we didn't have a failure, and we didn't see a failure on Kimi's car, so I'm fairly confident that we will be fine tomorrow," he said. "But we got caught out twice with the same problem.

"We didn't have it before, so it might be something related to the track here," he continued. "It also happened at the same place, at the end of the lap coming on to the main straight, so we need to have a look and understand what happened.

"It's a very high priority, and obviously it cost us five positions today, and if it happens again it will do the same again. It's something we need to fix. Plus, if it happens in the race, you don't finish."

Referring to his qualifying performance, he said: "I was on a very good lap but I lost the car at Stowe in the first run, trying a bit too hard, then in the second one I went wide in Turn 1 and lost the car from there.

"On this track it seems we are a bit behind, I think we have done good steps in the past, but probably not enough, also compared to other people, so I think there's a lot of catching up for us to do.

"We need to make the car quicker, to put more downforce in it, make it more efficient at the same time, and add a bit of power."

Known for his British sense of humour, he omitted to add the words... 'but other than that...'

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