Red Bull once again led the way in final practice ahead of qualifying for the U.S. GP
Vettel two-tenths clear of team-mate Webber in Austin
By Mike Wise at the Circuit of The Americas
Last Updated: 18/11/13 4:35pm
The World Champion lapped the 5.513km Circuit of The Americas in a time of 1:36.733s, with Webber 0.203s slower. Lewis Hamilton was third fastest for Mercedes while Nico Hulkenberg produced another strong performance in his Sauber to go fourth.
Romain Grosjean, who was slower than temporary Lotus team-mate Heikki Kovalainen on Friday, wound up fifth fastest overall. Kovalainen himself ended the session in 13th place about half a second off the Frenchman's pace.
Jenson Button was sixth fastest but the McLaren driver carries a three-place grid penalty into qualifying after overtaking under red-flag conditions in P1. Team-mate Sergio Perez was P8, with Mercedes' Nico Rosberg splitting them.
Valtteri Bottas was an encouraging ninth for Williams while Adrian Sutil completed the top ten in his Force India.
Bubbling under was Fernando Alonso after an anonymous session for Ferrari. The Spaniard was a second off the ultimate pace in 11th while Felipe Massa ended the session 17th directly behind Force India's Paul Di Resta.
Although there was mist in the air leading up to the start of the session, there was thankfully no repeat of Friday morning's delay.
Conditions were warmer and more humid and although they are forecast to climb still further on race day, it remains to be seen whether there will be any significant knock-on effect on tyre wear.
As things stand, Pirelli's rubber is proving very durable with drivers able to improve their times during multi-lap runs.
That suggests the same will be possible during qualifying, but with Red Bull and Vettel once again appearing odds-on favourites for pole position, the main interest is in seeing how the likes of Hulkenberg, Bottas and the Ferrari drivers might perform.
Hulkenberg was right up there on both tyres while Bottas was third fastest on the hard-compound rubber earlier in the session.