Martin Whitmarsh, the McLaren-Mercedes team boss, believes that his two drivers will have an advantage in Brazil this weekend because they have fresher engines.
All five of the drivers in title contention have used their allotted eight engines for the season, with the use of a ninth carrying 10-place grid penalty.
However, Lewis Hamilton and Jenson Button's available V8s have relatively low mileage.
Hamilton is 21 points behind championship leader Fernando Alonso's Ferrari, while Button is 42 adrift of the top of the standings, but Whitmarsh is bullish of his team's chances in Sunday's race in Sao Paulo.
"Mercedes-Benz have done a great job," he told formula1.com.
"We will not expect engines to run more than two race distances in races until the end of the season. Certainly, some of our competitors are going to have more mileage on their engines and their engines classically have not been quite as reliable as the Mercedes-Benz engines.
"So I think there's a potential advantage that we have there, but that can change in one revolution of an engine."
Mark Webber, the Red Bull-Renault driver, took a fresh engine for the Korean Grand Prix two weeks ago, and having spun out of the race on lap 18 will have only done limited mileage on the unit he will race in Brazil, meaning that he can confidently use a leaner engine setting to gain more speed on the straights without fear of unreliability.
Both Alonso and Vettel, Webber's teammate, will have to use engines that have already run the race distance at least twice, both in Brazil and in Abu Dhabi the following weekend, meaning neither will be able to push to the limit as much as they would like.
Meanwhile, Hamilton is still holding out hope of winning his second championship, despite the large deficit he has to his former teammate Alonso.
"I admit we have had some tough races this season and we could be in a much better position, but we are not. That's just the way it is," he said."We've now two races in which we can get 50 points, and we've just got to go and get them. We have the most determined and ambitious team I have ever known, so I think we stand a very good chance."