Mercedes have explained why they chose to bring Lewis Hamilton in for his Russian Grand Prix pit-stop earlier than he wanted.
The six-time World Champion was enjoying the soft tyres on which he started the race and said on the team radio he was happy to stay out in the lead, to try and build up a bigger gap over his team-mate Valtteri Bottas.
Ultimately, it was academic because a 10-second penalty for conducting two practice starts in the wrong place cost Hamilton any chance of finishing higher than his eventual P3 behind winner Bottas having dropped down to P11 when he stopped on lap 16.
Andrew Shovlin, Mercedes F1’s trackside engineering director, revealed the team had been concerned about the performance of the soft tyres dropping off.
“The rear left was at the limit on his car,” said Shovlin, quoted by Autosport. “There was very little rubber left on it, so it would have done one or two [more] laps.
“What we noticed in Russia is that actually the drivers don’t lose a lot of grip until you get down to the under-layer of the tyre and then you lose a lot of grip. So when it drops, it’s quite sudden.
“With the penalty, you’re looking a long way back actually at the cars you are racing, but as soon as you drop then they will start being able to sort of undercut you effectively.
“That was the big reason – it was principally what was going on behind him.
“He was down to one or two more laps on that tyre and then you would have found that the field, especially any cars that were on the medium, would start to be actually gaining race time on you.
“So it’s just about minimising the number of cars you will subsequently have to pass.”
Shovlin added that Mercedes had not expected to have a clear advantage over their main rivals Red Bull at Sochi.
“Our car seems to work pretty well at most places,” said Shovlin. “I know Red Bull were saying ‘this is a Mercedes circuit’.
“It may be a bit that it didn’t suit their car. We are not really sure why we had good pace.
“I think the race pace was strong, Lewis’s pace in qualifying was very strong.
“The C5 tyres, the softest compound, are not the easiest to get the lap together and to get everything in the right window.
“Valtteri struggled in qualifying with that in particular. I don’t think it really cost him because third on the grid is pretty competitive – very equivalent to second, arguably a bit better. But the car was pretty good there.”