McLaren driver Lewis Hamilton says he is prepared to take a cautious approach to winning the Formula One title as the season moves towards its climax.

Hamilton said second place on Sunday in Valencia to Felipe Massa's faster Ferrari gave him some "useful" points.

"I've actually extended my lead in the championship despite losing two points to Felipe," Hamilton said.

"I'm mentally strong enough to deal with that and I'm more relaxed about it, too. I'm playing a long game."

The 23-year-old is six points ahead of Massa, with the Brazilian's team-mate Kimi Raikkonen a further seven behind.

Going into Valencia's European Grand Prix, Hamilton was five points ahead of Raikkonen and eight ahead of Massa.

And with six races left - and a maximum of 60 points available - Hamilton says he will not try to force victories when his car is not fast enough.

"Clearly, I want to win all the time," said Hamilton in an interview on his official website. "But I've learned that sometimes it's more advantageous to score as many points as possible and live to fight another day.

"My aim is still to win the world championship and you don't do that by ending up in the barriers after making an opportunistic move."

In Valencia, Hamilton was never in a position to challenge Massa, who dominated the race from the start.

But the two teams have been closely matched for much of the season, with the advantage swinging between them from race to race.

And all the title contenders believe reliability could be the deciding factor in the title chase.

Raikkonen's engine failure while he was lying fifth in Valencia was Ferrari's second in consecutive races, after Massa lost a victory in Hungary with the same problem.

Hamilton said: "As you can see, reliability is the key. I'm not worried about the reliability of my car, because for the past 18 months we've had phenomenal reliability.

"We've not really got any problems which means we can focus on developing the car rather than worrying about reliability, which is a bonus for us."

McLaren managing director Martin Whitmarsh said results could depend on something as subtle as ambient temperature.

"I think Ferrari were pleased the sun came out on Sunday," Whitmarsh said, "as I'm sure they feel when the track temperature really heats up that's when their car really comes to them.

"We're now entering extremely interesting territory where we wont be entirely certain what sort of temperatures we'll be encountering at some of the future races.

Monza is likely to be hot and Singapore will probably be cooler, but the races at Spa, Fuji, Shanghai and Brazil could just as easily be sweltering as torrential.

"Regardless, we will continue to make changes to our car right through until Brazil."

The next race is the Belgian Grand Prix on September 7.