AUSTIN (AP) — The car, the math and the history all favor Lewis Hamilton at the United States Grand Prix in his pursuit of his second consecutive Formula One World championship.

Hamilton’s Mercedes has dominated the grid once again in 2015 with nine victories so far. Those wins have him sitting just a few points shy of clinching the world title on Sunday if he can keep just the right distance between himself, Ferrari’s Sebastian Vettel — who is already facing a 10-spot starting grid penalty — and his Mercedes teammate Nico Rosberg.

And don’t forget, Hamilton has already won at the Circuit of the Americas two of the last three years.

All those factors have led to an air inevitability that Hamilton will once again be crowned world champion Sunday or soon after. So much so that he only fielded one question about the title chase Thursday during the drivers’ news conference.

Sensing no reason to talk about a victory before a race is run, Hamilton sidestepped the question, even though a third title would put his name among the elite in Formula One history.

“Just happy to be here,” Hamilton said. “I always enjoy myself here in the states.”

Hamilton will win the title this week if he outscores Vettel by nine points and Rosberg by two. For example, if Hamilton wins and Vettel finishes third or worse, Hamilton clinches the title.

Those chances got a big boost Thursday when Ferrari announced it will outfit Vettel and Kimi Raikkonen’s cars with new engines for the rest of the season. Because Ferrari had already used the season limit of four, a fifth penalizes both drivers 10 places on the starting grid Sunday.

Ferrari spokesman Alberto Antonini said Vettel’s three wins this season had already surpassed the team goal of two.

“Our basic goal has been fulfilled. Of course, there’s a price to pay. It will put us in better position for races from here on in,” Antonini said.

Vettel’s first season with Ferrari has helped the iconic team regain its form in 2015, even if it remains far behind Mercedes for the short term. His three victories have already equaled Ferrari’s total the previous two years, and he’s finished on the podium eight other times.

The surge pushed Vettel, a four-time world champion with Red Bull, into a distant second behind Hamilton in the driver championship. Sacrificing his slim title hopes in pursuit of more race wins and continued development for 2016 is the right course, Vettel said.

“The policy was always to have the maximum power at every single race,” Vettel said. “We have to take the hit here.”

All the teams will be watching the weather, with the potential for heavy rain that could disrupt practice and qualifying Friday and Saturday. Some forecasts also call for rain Sunday.

“If we can start toward the front, I think we can stay there … if we’re not floating down the river,” said Daniel Ricciardo, who drove his Red Bull car to third place in Austin a year ago.

The U.S. Grand Prix will be the “home” race for American Alexander Rossi, who was granted a driver’s seat by small-budget team Manor Marussia for five of the final seven races of the year. After sitting out the RussianGrand Prix, Rossi was seated next to Hamilton at the news conference, which may be as close as he’ll get to him all weekend.

Rossi is the first American driver in Formula One since 2007 and his goal is to drive well enough the rest of the season to secure a permanent seat next year. That means trying to beat teammate Will Stevens, which he did in Singapore and Japan.

“The objective is just to continue what we’ve done,” Rossi said. “I’m really only racing one other car.”