Button confident of Spanish title defence

Jenson Button is upbeat about his Spanish Grand Prix title defence this weekend, while Sebastian Vettel and Fernando Alonso are hoping that reliability won't compromise their chances of victory.

Button, the world champion and current Formula One leader, feels "pretty well prepared" for Sunday's race, with McLaren carrying out upgrades to a car that gave the Briton his second victory this season in China.

Button leads the championship with 60 points going into the European leg of the calendar, with Nico Rosberg of Mercedes, Alonso and McLaren team-mate Lewis Hamilton all within 11 points.

"Basically I didn't know where I'd be after four races so I'm very happy. But it can easily swing around," Button said yesterday. "I don't feel any pressure at all. But I can't rest – it has to be flat out from here on."

Vettel, on 45 points, arrives at the Circuit de Catalunya in good shape as Red Bull have started from pole in each of the season's first four races, although reliability problems have left him with only one win from three starts at the front of the grid. Qualifying is key in this race, with the last nine winners having come from pole.

"Pole is always important [because] where you put the car on Saturday will determine your race result quite a bit on Sunday," Vettel said. "[But] the target is the same – start from pole and try to win the race."

Like Red Bull, Ferrari have had technical problems but Alonso believes the Italians can deliver at a track where the Spaniard won four years ago. Alonso will try out a new rear wing in today's practice before deciding whether to use the aerodynamic upgrade that has so far given McLaren a slight edge.

"Hopefully we can have no problems with the engine," said Alonso. "We need to maximise our potential in the coming races. We have a very strong car but maybe we didn't take all the points we should have."