Lewis Hamilton bemoaned his "peaky" Mercedes car after an underwhelming Mexican Grand Prix qualifying result.
Both Hamilton and team-mate George Russell were pleased with their car upgrades last weekend in Austin. But the Silver Arrows struggled to get the same sort of feeling in practice at the Autodromo Hermanos Rodriguez.
And that continued into qualifying. Both Brits reached the final part of the session, but Hamilton was only sixth fastest on the road and faced a potential penalty for a yellow flag infringement, while Russell is set to start two places further back on the grid.
"I've been struggling all weekend with the car and it has been a bit of a nightmare to drive," said the disappointed seven-time world champion after qualifying. "We've had to try and put the performance together piece by piece, and we made good changes going into qualifying so that I was much happier with the car.
"Q1 and Q2 weren't looking too bad, especially the second run in Q2. But the car is just really peaky – sometimes it's in the window, sometimes not. And I couldn't squeeze anything more out of it on that final lap.
Sebastian Vettel warns of looming F1 ban and is "very worried about the future""The race is definitely going to be a challenge – we will be overheating the tyres and the brakes, so it won't be easy to battle the cars around us. I don't really know what kind of race to expect but it's going to be on a knife edge."
Russell was also visibly disappointed with the fruits of his labour. "It was a bit of a shame to end up P8 because we showed signs of strong pace at points, but we didn't deliver when it counted," he declared. "We lacked consistency today – some runs we were strong, others not, so it was a confusing picture. On the final run, we had one set of new tyres and tried something different on the out lap and it didn't work and the tyres weren't in the window.
"As for [the race], it will be hard from P8. The brakes will need managing and PU temperatures are always a challenge, too. We came here expecting to be competitive and I hope we can make progress in the race, but it won't be easy."
And team principal Toto Wolff felt there was more on the table for both his drivers. The Austrian said: "P6 and P8 are less than we had hoped for from qualifying today. We made some good steps with the car today, but we couldn't put the lap times together when it really counted.
"We are less than three tenths off pole, but it feels like a lot more given our starting positions. We showed some decent race pace yesterday, but we don't know if that will translate tomorrow after the set-up changes we made. But the only goal will be to move forward from where we start.