Mercedes has admitted to being totally baffled as to how Lewis Hamilton was able to post a new lap record on the last lap of Sunday's British Grand Prix on hard tyres that were 32 laps old.

Usually the Briton is heard expressing concern at his tyres, but on Sunday, going against team orders, he stayed on his hard tyres, and already assured of victory in his home race posted a new lap record for good measure. Indeed, his time was 0.037s quicker that that posted by teammate Valtteri Bottas just two laps after stopping for (used) softs on lap 45.

"We truthfully have no idea at all how Lewis did the fastest lap of the race on 32-lap old, hard tyres," admits the German team's chief strategist, James Vowles.

"The hardest tyre available, completely used up and yet he does a fantastic lap at the end," he continued. "Well done to him, no idea.

"Because we weren't expecting him to do that fastest lap of the race on 32-lap old hard tyres, we did actually plan for him to do an extra pit stop towards the end. It was a free pit stop," he admitted. "Valtteri behind had to stop anyway, he'd only run mediums at that point, so had to complete the requirement for the race of using another compound.

"With Lewis, we very much called him in with the intention of that, giving him a fresh set of tyres and going for fastest lap. He was very comfortable with how his tyres were behaving however, which is why ultimately, we left him out and as you saw, he did the fastest lap irrespective."

Meanwhile, team boss Toto Wolff admitted that Hamilton's achievement "made the data look silly".

"Fastest lap with 32-old hard tyres is very surprising," said the Austrian. "We tend to have a laugh as the engineers have their new presentation in our Sunday morning meeting which basically says you don't need to go for fastest lap, it doesn't make sense anyway. And then he pulls one out like this which makes the whole data look a little bit silly, but it's just his ability."