DC puzzled by McLaren's changing pace

Coulthard, grabbed the final podium place behind Michael Schumacher and Juan Pablo Montoya in Suzuka to end the season a career-best second in the championship, but he was never in the hunt for victory in the last race of the season.

Third place - achieved after team mate Mika Hakkinen let him through in the final few laps - secured his first runners-up spot after coming third four times.

"It is difficult to make a comparison with different tyres so to compare us with Williams is quite difficult and clearly they have been strong in other areas, not just the car," he said. "But between us and Ferrari it has been unusual because there have been some tracks were we have been very competitive with them and others, like here, where there is a big, big difference. It is a little difficult to fully understand that."

But the 30-year-old said he was happy with his own performance and asked if this had been a satisfactory end to an unsatisfactory championship he said: "Yes, I did everything I could this year and second place was the best I could do.

"There was a big gap to Michael. But I was helped a little at the end by Mika, which was nice. But at least I have finished the season on the podium. To win would have been fantastic, but I've never been that good around Suzuka so it isn't a bad result."

Coulthard was second with 65 points to Schumacher's 123 - giving the Ferrari ace yet another record with the biggest winning margin in history.