Mercedes F1's One-Stop Gamble Stumbles in Japan

Mercedes F1’s one-stop plan at the Japanese GP failed due to the W15’s hard tire issues.

Mercedes F1 was hoping for a one-stop strategy during the Japanese Grand Prix, but this was thwarted by the W15’s inability to get the hard tires to work in the first stint. Andrew Shovlin, the team’s trackside engineering director, explains why this attempt, albeit unsuccessful, was a sound approach.

“Primarily, we thought it would be a way to be a bit different,” Shovlin explained. “The teams in the top 10 with two hard tires were us and McLaren. Red Bull and Ferrari had two mediums and at that point, there wasn’t enough data to compare the hard and medium tires.”

Mercedes opted for hards during the stoppage to try two hard-tire stints with a single stop: “It was certainly going to be easier to achieve a single stop with two hard tires than with one medium and one hard tire, and thanks to the red flag, we had already used the medium tire.”

“Then, looking further down the grid, there really wasn’t a threat from the other teams. They were slower than us and unlikely to interfere, so it was really about making up for it.”

“We weren’t fast enough.”

Shovlin admits that the poor pace at the end of the first stint was also due to traffic: “The problem is that the end of our stint wasn’t good enough. We lost quite a bit of time in traffic, but fundamentally, we weren’t fast enough and we’re trying to understand that now.”

“The tires at Suzuka are quite challenging. There’s some overheating and when there’s traffic, the grip decreases, there’s a bit more sliding, and we struggled in the slower corners. There’s a hairpin turn, and the slow chicane too.”

“That’s where we lost a good chunk of our time. It was difficult to get the car to turn and it was costing us a bit in those two corners. And then, obviously, as the tires age, the sliding increases and the temperatures are a bit higher, which only made matters worse.”

For now, Mercedes has not resolved why the W15 was so hard on its tires: “I wouldn’t say we have a complete understanding of this issue at the moment. It’s obviously very soon after the race.”

“That’s one of the tasks we’re going to tackle in the coming days as we try to understand exactly what happened and why we dropped back much more than Leclerc, for example, who had a very good first stint that was much longer.”