AUSTIN -- After the opening practice sessions at the Circuit of the Americas, Lewis Hamilton believes Red Bull is a bigger threat than Ferrari at this weekend's U.S. Grand Prix.
Hamilton topped both Friday practice sessions in Austin, finishing the dry afternoon session 0.4s clear of Max Verstappen's Red Bull in second. But while Mercedes had the edge over one lap, the race simulations told a different story with Red Bull looking faster than Mercedes on heavy fuel.
Hamilton's title rival Sebastian Vettel was limited to just eight laps in the afternoon session due to a handling issue on his Ferrari, which meant meaningful long-run comparisons were not possible. However, on the basis of what he's seen so far, Hamilton thinks the Red Bull looks like the car to beat on Sunday.
"I think the Red Bulls at the moment are the ones who look quickest," he said. "We didn't really do a huge long run to be honest. We had a problem, so that's why we had to stop halfway through. But the little bit that we did, it looked like we were relatively close to the Red Bulls.
"Overall it was a good day and I was happy in the car. I was making good steps forward in terms of the balance and the way it was changing. I definitely started on the right foot for the weekend, so we will see how we continue."
But even if the Red Bulls are close to Mercedes on race pace, they are unlikely to be able to rival Hamilton in qualifying. Unlike Mercedes' power unit, Red Bull's Renault engine does not have a more powerful engine setting for qualifying and the car has only once qualified on the front row of the grid this season.
Hamilton hopes that will give him an advantage on Saturday, but he is wary that overtaking is easier at the Circuit of the Americas than most other tracks.
"Positioning is everything, and naturally starting from first and getting to the first corner first, the chess game is completely different from there with a perfect first move," he said. "So qualifying's definitely been good [this year], but it's the Fridays that have really made that Saturday possible, starting on the right foot, making the right setup changes and not getting lost on the Friday often bodes well for the Saturday.
"When you go from race to race, there's always a calculated delta of pace you have of have to overtake the car in front. That shifts all over the place. Here's it's around eight-tenths of a second you need to be quicker than the car in front. That's quite low compared to the other circuits. Lots of other circuits you need to be 1.8 seconds faster than the car in front to be able to pass. It's quite often over the one second mark."