SILVERSTONE, England (AP) - Formula One championship leader Sebastian Vettel was the fastest on the final day of a special in-season testing session with new tires.
The three-time defending series champion completed 78 laps in his Red Bull at Silverstone on Friday during the tire test sanctioned by the sport's rulers to quash the threat of a revolt by teams.
Vettel topped the timesheets with a lap at 1 minute, 32. 894 seconds. Adrian Sutil set the pace in the morning, but ended up second-fastest, around three-tenths of a second slower than Vettel.
In-season testing was banned in 2009 over cost concerns, but these unprecedented sessions were allowed to allay safety fears after concerns about tire blowouts on the same circuit at the British Grand Prix earlier this month.
Mercedes was banned from the sessions after holding unsanctioned testing in May.
The new compound of tire tested at Silverstone will be used from the Hungarian Grand Prix next weekend and for the rest of the season.
``We had three days of testing with a lot of different drivers in a lot of different cars and no failures - in conditions that were hotter than the (British) Grand Prix - so that's good,'' Vettel said. ``Obviously, we were very limited on what we could do, but for me there is not that much difference with the tires. It was good to get in some laps though, good to get a feeling for them.''
Sixth-fastest was Felipe Massa, who is seeking a strong second half of the season to secure his future at Ferrari.
With 10 races of the season's 19 races still to go, the Brazilian said showing more consistency on the track could be key to landing a deal for 2014.
Massa is already 100 points behind Vettel, and 66 adrift of second-place teammate Fernando Alonso.
Since finishing third at the Spanish Grand Prix in May, Massa has collected 12 points from two races and failed to finish the other two.
``I know what I have to do, I'll just concentrate to do good results,'' Massa said. ``The pace is there, so I'm not worried about the pace ... we are trying to improve the car in the best way possible, and I need to improve a little bit more.''
And ensure ``nothing strange'' happens in races. Like issues with the tires.
``The (new) tire is a little bit more consistent, that we could see here,'' Massa said. ``The consistency on the long run is a lot better than the race here at Silverstone ... nothing happened here on the tires - blowing, punctures everything that we were seeing in this race (the British GP).''
The sight of large chunks of debris showering cars and, in one case, a huge strip of rubber flying across the track, almost led to the race being called off earlier this month and prompted concerns F1 was sacrificing safety for excitement.
The tire trouble at Silverstone was the latest controversy to hit F1's sole tire provider, which has come under fire over fears that its products are wearing down too quickly and leading to races being decided by pit stops rather than action on the track.