Kimi Raikkonen believes it will be hard for Ferrari to keep third place in the championship despite his fourth position at the Japanese Grand Prix.
The Finn enjoyed a strong race to finish behind McLaren rival Lewis Hamilton, whose team is now just two points behind Ferrari with two races left.
Raikkonen admitted he was comfortable with his car today, but claimed it was lacking speed to beat Hamilton.
"Today the car wasn't bad, but it was not quick enough to fight for the podium," said Raikkonen. "This fourth place is useful in terms of keeping the team in third place in the Constructors' Championship, but it will be hard to hang onto it over the final two races. I will definitely do everything I can though.
"I was unable to make up places at the start, especially as the first corner is not that far from the start line and so I was unable to make the most of the KERS.
"In the first stint, when I was on hard tires, the situation was a bit difficult, but then, once on the softs, things improved considerably.
"I managed to close on Heidfeld and pass him at the pit stop, even though, coming away from my stop, I found myself in traffic behind Button. Then there was not much to fight for to the end of the race."
Teammate Giancarlo Fisichella finished outside of the points again, down in 12th position, but the Italian said he was happier with his race pace.
"I had a better feel for the car this weekend and I think the effect from that could be seen, although maybe not in terms of the results," he said.
"Today, I could run at a good pace, especially in the middle part of the race. It's a shame I lost a place in my battle with Kovalainen. We managed to get ahead of him in the pit stop, but then he swerved across to the inside at the only point where I left the door slightly open and he leaned on me, managing to get by.
"Towards the end, I had to fight off Sutil who was very quick and was on the soft tire, while I was on the hard: at this point the KERS came in handy. Now I am looking forward to Interlagos in a more confident mood: it will be important to get a slightly better start position to try and finally make it into the points."