Why did Mercedes fit Hamilton with Mediums in Monaco?

Mercedes Formula 1 strategy chief James Vowles has explained the team’s decision to fit Lewis Hamilton with Medium tyres for the majority of the Monaco Grand Prix.

Hamilton held on to take a dramatic victory in Monaco on Sunday after struggling with tyre wear for much of the race, making a set of Mediums last 67 laps while keeping Max Verstappen – who was running Hard tyres – behind.

Mercedes confirmed after the race that it would review its tyre call, with Vowles offering a full explanation in the team’s regular post-race ‘Pure Pit Wall’ video.

Vowles said that the team’s tyre data gained from Hamilton’s Medium tyre runs in second practice on Thursday suggested he would be able to get to the end with no problems.

“We were one of the top teams to have both Medium and Soft available to long run in FP2, and the track conditions were slightly worse than they were going to be in the race but still representative enough to understand how the tyres were performing,” Vowles explained.

“On those long runs that we did on Medium, we were able to see that the life would just about make what we needed to in the race to achieve the stints that happened when the Safety Car came out. And that’s what triggered our decision.

“In Monaco, you typically want the softest rubber you can get away with for the stint length that you are trying to get to. And we knew it would be tight, we knew it would need a lot of management but believed based on the Thursday data that the Medium tyre would do the job.”

The threat of rain – estimated to be at 90 percent before the race – also prompted Mercedes to go for the softer compound in case it hit the circuit.

“If you could see our weather radar, you would’ve seen the sea of blue come in from the east towards the circuit,” Vowles said.

“Now, it actually broke up. There was a very little bit of light rain during the race but we had forecasted that there was going to be slightly heavier than that. Not enough to go to inters but enough to be very difficult on dry tyres.

“The Medium may well have provided slightly more coverage in those conditions being a slightly softer compound and that’s why we erred towards that slightly softer, Medium tyre.”