Four-time world champion Sebastian Vettel conceded on Saturday that he felt out-classed by his Ferrari team-mate Charles Leclerc in qualifying for the Portuguese Grand Prix.
The German driver, who on Thursday said he is hoping to end his "love affair" with the Italian team "with dignity" at the end of this season, wound up down in 15th on the grid while Leclerc was fourth.
"It's not just beating, it's like a different class," he told Sky Germany. "I try everything I can. I think the laps I hit -- and I'm satisfied with them -- are still too slow.
"At the moment, there is nothing more I can do than to get what I have inside me."
He said he had faced difficulties in bringing his set of medium tyres up to temperature, but he could not explain why.
"I don't know why I have such a hard time getting the tyres up to temperature and it feels a bit different every time," he went on. "As I said, the car felt good the first time I tried it.
"I thought that with the medium I could easily repeat the time of Q1. That was the target, but it wasn't that easy."