NUERBURGRING, Germany — Formula One drivers threatened to withdraw from the German Grand Prix if there are more tire blowouts during Sunday's race.

Last weekend, a number of blowouts overshadowed the British GP, causing tire supplier Pirelli to introduce a new plan to stop the same thing from happening again.

But the Grand Prix Drivers' Association said Thursday in a statement that the drivers would pull out if the problem persists.

"We are ready to drive our cars to the limit, as we always do, and as it is expected by our teams, sponsors and fans," the GPDA said. "However, the drivers have decided if similar problems should manifest themselves during the German GP, we shall immediately withdraw from the event, as this avoidable problem with the tires endangers again the lives of drivers, marshals and fans."

Pirelli moved quickly to address the problem, and a different type of tires will be used for Sunday's race, hoping to address the problems and appease angry teams.

The German GP, which alternates between Hockenheim and Nuerburgring, arrives at the latter in the Eifel hills with the storied circuit officially bankrupt. The only reason the race is taking place is because F1 chief Bernie Ecclestone decided to accept a smaller fee for the right to stage it.

Ecclestone has indicated he will come to the race, although he faces possible bribery charges from Munich prosecutors. Ecclestone skipped last year's race at Hockenheim.

Hamilton won the previous F1 race at the Nuerburgring in 2011. The British driver is still winless since switching to Mercedes this season.

Hamilton described the tire incidents in Silverstone as "unacceptable," but the former world champion welcomed the reaction of Pirelli.

"I am satisfied, but only when we get there (Germany) will we have a better idea how it is for us," Hamilton said. "Everyone is in the same boat, but I'm glad action has been taken.

"It's still a concern. We'll see how the weekend goes but I'm sure they've taken the right steps to make it safe."

In Germany, Pirelli will use a Kevlar belt — a fiber that is more resistant to punctures — instead of steel on its rear tires.

From this month's Hungarian GP on July 28 onward, the Italian manufacturer will revert to the type of tires it used in 2012 combined with the current compounds from this season.

"I'm confident the right decisions will be taken because safety is a very important factor," said Mercedes' Nico Rosberg, who won in Silverstone. "(Pirelli) will have everything under control for the Nuerburgring."

Pirelli said the teams contributed to the tire failures at Silverstone by mounting the tires the wrong way around — putting the less resilient inner wall on the outer edge — and having their tire pressures too low, increasing friction.

"Surprisingly, the Nuerburgring is one of the circuits that we have the least experience of, having only raced there once before in Formula One, but we're certain that we have chosen the correct compromise between performance and durability by bringing the medium and soft compounds," Pirelli motorsport director Paul Hembery said.

While insisting that the steel-belted version is completely safe when used correctly, Hembery said the Kevlar-belted version is easier to manage — "we prefer to bring a less sophisticated tire."

Ferrari's Fernando Alonso, who finished third in Silverstone, said he was sure there would be an improvement.

"I know that various modifications have been applied and let's hope that means all of us drivers can race in safe conditions," Alonso said. "At the moment, we can't make any predictions, because no one has tried them and we don't know what and how many benefits they can bring, apart from trusting in the fact that it won't be dangerous to race."

Vettel has never won in Germany; in fact he hasn't won in Europe in 22 months.

At Silverstone, Vettel retired when leading in the closing stages due to a gearbox breakdown. But he still leads the championship after eight of 19 races and has three wins this season.

The German has 132 points but Alonso cut the gap in Britain and has 111.

"We have to regain the lost points as soon as possible," Vettel said.

Rosberg, who has won two of the past three races, said he wasn't that concerned with the choice of tires.

"With the car we have it doesn't matter which tires we use because we have a very quick car in general so I am confident we can stay where we are, more or less," Rosberg said.