After the final safety car in Sochi Ferrari put Leclerc onto fresh soft tyres – as already used by both Mercedes drivers – in the expectation that he could get past Bottas and then potentially attack leader Lewis Hamilton.
However despite the superior straightline speed of the Ferrari Leclerc was not able to get past, thanks to the “perfect job” of defending that Bottas was able to do over the final laps of the race.
“After Leclerc stopped and fitted that soft tyre, [it was] Mercedes, Mercedes, Leclerc on the Soft,” Vowles explained in a Mercedes video.
“At the restart it was clear we were going to be in a certain amount of pressure and trouble from the Ferrari.
“They are extremely quick in a straight line and especially on the run down to Turn 2, and with a DRS that opens several laps after the safety car, we thought it would be incredibly difficult to hold onto that position to the end of the race.
“Valtteri didn’t make a single mistake. He didn’t lock the brakes going into Turn 2, he defended in every corner as he needed to. More so, he was continuously going up and down on the energy systems in order to maximise his speed down into Turn 2 and he did it perfectly.
“Leclerc backed off several times, you would’ve seen that, just to cool the tyres down and have another opportunity, build his battery back up and attack again. And every time he did, Valtteri responded with the same switches on his side, dog fighting to the end of the race, and [he] did a perfect job.”
The Finn’s successful defence also helped Hamilton set fastest lap.
“Valtteri had done such a good job defending to Leclerc behind that Lewis was able to look after [his] tyres and keep them in a very, very good state.
“And towards the end of the race as he required all the pace from the car and the engine to do his times, the tyres were in such a good state that he was able to deliver quite a competitive fastest lap as a result.”
Hamilton’s victory was in large part due to the choice of using medium tyres for Q2 and this the race, as it allowed the silver cars to run long and potentially benefit from a safety car.
While that it how the race played out Vowles admits that Mercedes expected Ferrari to struggle more with the softs.
“Going into the race, we expected that soft tyre to be a little bit more fragile then it was. In reality, the degradation was very low on both the soft and the medium and that reduced the opportunities that we had.
“Had the soft degraded a lot like Friday, we would have had plenty more to play with. It would’ve meant around about lap 15 or so, that soft tyre from the Ferraris would’ve started to fail a bit more and would’ve come back towards us and they’d have had to stop earlier, creating more of an offset.
“It didn’t, so once they were able to go a fair amount into the stint, now we were reliant on the soft tyre transforming our car and making it work better. But even so we would’ve been behind Ferraris.
“Had there been a late safety car, and all the cars bunched together, that fresh soft may have provided the difference. Whilst we didn’t have necessarily the track position on them, if we were tucked up behind them, I think that tyre would’ve restarted very well.
“Indeed, one of the reasons why Leclerc stopped and fitted that soft tyre instead of staying on that medium was he had concerns about how it would restart.”
Vowles admits that without an intervention, Mercedes would not have won: “The reality was, though, I think it would’ve been incredibly tough to take points of Ferrari in a straight fight without a VSC or a SC. I think we would’ve finished third and fourth and Ferrari would’ve won that race.”