Worries about Pirelli tires after multiple blowouts at the British Grand Prix are dominating the conversation at Nürburgring ahead of this weekend's German GP, the ninth race of the 2013 Formula One season.

Drivers Lewis Hamilton, Felipe Massa, Jean Eric Vergne, Sergio Perez and Esteban Gutierrez all experienced rear-tire blowouts during last Sunday's contest at Silverstone.

Some drivers talked about boycotting the German Grand Prix unless Pirelli took steps to solve the problem.

The company responded by announcing that the rear tires to be used on the Nürburgring course will have inner belts made of Kevlar, not the steel belts employed in the British Grand Prix.

Germany's Sebastian Vettel, a three-time F1 champion, enters his home race with 132 points in the 2013 competition, well ahead of Spanish double-champion Fernando Alonso, who has 111 points.

Even so, Alonso won the 2012 German GP, held at Hockenheim.

The Spaniard was cautiously optimistic Thursday on Pirelli's moves to remedy the tire problem.

"After what we saw in Silverstone, we now go to the Nürburgring, confident we can see an improvement," Alonso said in quotes post on the Web site of his Ferrari team. EFE