Red Bull take care over Vettel
Red Bull are poised to take measures to ensure Sebastian Vettel's title bid is not wrecked by unreliability in Sao Paulo.
Although Vettel extended his lead over rival Fernando Alonso to 13 points following a second-place finish in the United States Grand Prix, team-mate Mark Webber retired with an alternator failure.
As Vettel was forced out of both the European and Italian races with the same issue - the former when leading - there is now real concern within the team he could be pipped at the post by Alonso in Brazil due to another alternator issue.
Engine suppliers Renault recently developed a new specification of the device that was run successfully in Austin by two of their other customers, Lotus and Caterham.
Red Bull, however, opted for the older-spec model, a case of better the devil you know, only to suffer with Webber retiring.
For Interlagos, it appears certain Red Bull will now switch to the new spec alternator.
Asked for his thoughts on the matter, team principal Christian Horner said: "It's just a worry, full stop.
"Unfortunately it is the third alternator (failure) we've had and there have been others in other cars.
"The new version has raced on other engine cycles and hopefully that's what we'll have for Brazil."
There are no guarantees, however, the new model will prove any more reliable as Red Bull's chief technical officer Adrian Newey said: "The component is not a new component.
"It has been on the Renault engine since about 2005 and it has been failing since 2005 as well."
Renault's head of trackside operations Remi Taffin sees no reason why Red Bull will not turn to the new device.
"It is very simple. We go for the new spec. It has passed all the tests," said Taffin, speaking to Autosport.
Explaining why Red Bull did not fit the new alternator ahead of the race at the Circuit of The Americas, Taffin added: "Because they are human beings and at some point as humans they have some feelings.
"It was a common decision, so we put everything on the table and we decided altogether we should go that way. We had everything to fit either the old or new design.
"But the feeling was generally there is some sense to keep on using something we have known for years with low mileage and stuff like that, even if we had a new solution that we knew had gone through all the tests.
"Sunday was the first time it had been used, but now we are up to 2000km on a few items with track and dyno testing, so there is nothing we would do more on this item before we fit it on the car."