United States GP: Kovalainen sure Caterham will beat Marussia

The Finn qualified down in 22nd position, while team-mate Vitaly Petrov managed one place better.

Both men, however, qualified behind the Marussias of Timo Glock and Charles Pic for the first time this season.

But Kovalainen insisted this did not mean Marussia was now faster.

"Qualifying today was as expected, struggling to get the tyres working on short runs," he wrote on his Twitter account, "but tomorrow we will beat both Marussias. We are the better team."

The Finn said Caterham's qualifying strategy had not worked.

"We underperformed today, it's really that simple," said Kovalainen. "We went with a plan that didn't work and unfortunately both Vitaly and I weren't able to get enough heat into the tyres to get the best out of them, or manage the traffic well enough to get a clean lap in.

"Tomorrow's another day so now we need to regroup and have a better performance in the race than we did today."

Petrov also blamed traffic issues for failing to achieve a better result, and reckons Narain Karthikeyan's HRT stopping at the end of the session also hurt him.

"Quali obviously didn't go how we wanted it to," he said. "I had traffic issues on every lap and wasn't able to put a clean lap together, but even without that we've struggled with the tyres here all weekend and that showed today.

"It was bad timing for us that the HRT stopped on track just when Heikki and I were on our quickest laps and having been stuck behind them, but you can't plan for that so we need to put today behind us and hopefully we'll be better tomorrow."