BMW's cars held up Hamilton during the race but were not excluded

Ferrari's Kimi Raikkonen won the race to edge out Hamilton, who finished seventh, for the drivers' championship.

Race stewards then investigated alleged fuel irregularities by Williams and BMW Sauber, but decided not to punish them.

Had they been disqualified, Hamilton would have finished fourth, earning him enough points to become world champion.

McLaren, who formally lodged an appeal on Tuesday, outlined their reasons for protesting.

"If we didn't lodge our intention to appeal we would have been criticised by F1 fans and insiders for not supporting our drivers' best interests," said Martin Whitmarsh, McLaren's chief operating officer.

He also said they were unhappy with the decision not to punish Williams or BMW Sauber.

"I want to stress our quarrel is not with Ferrari or Kimi Raikkonen, who won the race fair and square," added Whitmarsh.

"Our argument is with the race stewards in relation to Nico Rosberg, Nick Heidfeld and Robert Kubica."

Williams are pretty confident that their driver, Nico Rosberg, will not be thrown out of the race any time soon

BBC's Adam Parsons

McLaren notified motorsport's world governing body, the FIA, late on Sunday of their intention to appeal against the stewards' verdict.

The problems with the BMW Sauber and Williams cars centred on a technical infringement - a fuel-temperature irregularity - which could have given them an advantage.

Nico Rosberg finished fourth in his Williams while the BMW duo of Robert Kubica and Nick Heidfeld were fifth and sixth.

But after a three-hour hearing, the race stewards chose to impose no penalty on either team, ensuring Raikkonen could celebrate the first F1 title of his career by finishing one point ahead of Hamilton and McLaren team-mate Fernando Alonso.

"I've spoken to the Williams team and they are pretty confident that their driver, Nico Rosberg, will not be thrown out of the race any time soon," said BBC sports news correspondent Adam Parsons from Sao Paulo.

It's very unsettling to have this appeal, but there is so much at stake and the FIA have to find somehow a way of being consistent

Damon Hill

Former world champion Damon Hill has accused F1's race stewards of exercising double standards.

He feels McLaren have been on the wrong side of FIA decisions on more than one occasion this season while other teams have escaped censure.

"It does get quite difficult to see where the consistency lies," Hill told Radio 5live.

"If you go back to the beginning of the season, McLaren's argument is that Ferrari won the very first race using a device which was later found to be illegal by the FIA.

"They removed it but the result stood.

"It's very unsettling to have this appeal, but there is so much at stake and the FIA have to find somehow a way of being consistent.

"I can see how a couple of degrees fuel temperature can be regarded as being so negligible that it wouldn't make any difference.

"But we're talking about such tiny differences all the time in Formula One, there has to be a line where you're one side or the other."

Under FIA regulations, no fuel on board a car may be more than 10 degrees centigrade below ambient temperature - the prevailing temperature on the track.

If you put chilled or cool fuel into a car you get between 5 and 10 horsepower increase

Eddie Jordan

But in initial findings there was a clear discrepancy.

Heidfeld's fuel was 13C lower than ambient at his first stop and 12C lower at his second.

Kubica's varied by 14C, 13C and 13C at his three stops, while Rosberg's was 13C and 12C out at his two stops.

Cooler fuel can give a car a performance advantage.

It is denser, so it can take slightly less time to refuel a car or marginally more fuel can be added in the same time.

Cooler fuel would also give a slight power advantage for about three laps before returning to the temperature out on the track.

However, the total advantage for each car over the race distance was almost certainly no more than a second.

Former F1 team owner Eddie Jordan agrees that cars do gain an unfair advantage if they use cooler fuel but thinks McLaren will find it hard to launch a successful appeal.

He says it will be difficult to prove that the fuel temperatures at the time the fuel entered the cars broke the rules.

"If you put chilled or cool fuel into a car you get between 5 and 10 horsepower increase," he told 5live.

"Now that is a significant amount and would be enough to exclude a car if it was found to have done so, but I am not sure at this late stage how you can actually get that proof."

Hamilton could only finish seventh in the final race of the season at Interlagos after a poor start, hampered by an apparent mechanical problem on lap eight when he dramatically slowed at one point, almost to a stop.

He could be seen rocking in his McLaren, virtually willing it to get going, while all the time the field streamed by.

Whatever the problem, his car finally regained power, but he was left with too much to do.

Finn Raikkonen, 28, led home team-mate Felipe Massa in a Ferrari one-two at Interlagos.

Alonso finished on the same points as Hamilton, but the double world champion from Spain was third on countback.