Vettel sets early pace at Circuit of Americas
Vettel, who can clinch his third straight drivers' title on Sunday at the $400 million Circuit of the Americas, was quickly up to speed on the spectacular undulating 5.516km (3.4 mile) track carved out of the south Texas scrublands.
The 25-year-old German set the early pace in the morning with a best time of one minute 38.125 seconds then improved on that in the afternoon, despite missing much of the session due to a water leak, by clocking 1:37.718.
"It was slippery this morning and a bit like driving on ice. It wasn't so easy," said Vettel. "We had a bit of a problem this afternoon and so couldn't run as much as we wanted, but we got two good runs which is important for tomorrow and Sunday."
The champion's afternoon time, 0.7 seconds quicker than Australian team-mate Mark Webber in 1:38.457, underlined Red Bull's intention to end the title chase in Austin.
Ferrari's Fernando Alonso, 10 points behind championship leader Vettel and the only driver who can deny his German rival the title, had the third best time in both sessions to keep the pressure on his German rival.
McLaren's Lewis Hamilton, who won the last Formula One race held in the United States five years ago at Indianapolis, signaled he was ready to scrap for the victory again recording the second effort in the morning and fourth fastest in the afternoon. "This is a great drivers' track — it's very tough to pull together three perfect sectors," said Hamilton, a three-time winner this season.
The morning session, run in front of mostly empty grandstands, produced a few thrills as drivers came to grips on the slick undulating circuit. While the 90-minute practice finished without major incident there were plenty of spins and more than a few forays into runoff areas as drivers tested the limits of the track.