MONTMELO, Spain (AP) — Fernando Alonso is giving McLaren's struggling Formula One team six months to give him a competitive car.

If not, the two-time former champion says he will be looking for another team, or even to abandon F1 altogether.

"Around September, October I need to consider what I will do next year, if it is time to find challenges outside Formula One or if in Formula One I have the opportunity to win the championship," Alonso said Thursday, a day before practice starts at the Spanish Grand Prix.

Alonso is enduring a wretched start to the season. He didn't finish any of the four races, and hit a new low at the Russian GP when his McLaren broke down on the formation lap.

"(It was) really, really bad for us as a team not to start the race. Completely unacceptable," Alonso said, while ominously adding that he still didn't know what had caused the breakdown in Sochi.

Alonso, who has twice won at the Circuit de Barcelona-Catalunya, is hoping that McLaren's mechanics have worked wonders in the two weeks since Russia.

"Let's see what we can do here," Alonso said. "Definitely, our moment right now is not the best. Hopefully we finish with both cars and accumulate some mileage. Hopefully, this is the starting point of a new championship for us."

So much finger crossing for signs of progress appears wishful thinking for a team that has yet to score a point. And Alonso made it clear that McLaren must find a solution if it expects him to stick around next year.

"I am happy with the team but we are not winning," he said. "If from here to October I see the opportunity to win in 2018, I will be more than happy to stay with the team. If not, I will be happy to talk to anyone."

The 35-year-old Alonso ranks sixth all-time with 32 wins, but his last victory came at the 2013 Spanish GP while he was with Ferrari. He has struggled with inferior cars since, and his growing frustration has driven him to trading the endless twisting and turning of the labyrinth-like Monaco GP for a run at the Indianapolis 500 on an oval track later this month.

Alonso said he is eager to get in some more practice after passing the rookie orientation test for the Indy 500 last week.

"The driving technique is quite different," Alonso said. "I think that next week when we start the free practice with other people around I will build confidence and my understanding of what the car needs."

While Alonso gave McLaren his ultimatum, Sauber driver Marcus Ericsson expressed his concern over his team's decision for next year to use the same Honda engine that has plagued McLaren.

Sauber recently signed a multi-year deal with the Japanese engine maker to ditch its Ferrari power unit at the start of next year.

"It doesn't look like the best decision because Honda is struggling right now," Ericsson said. "But in the long term it could be a good deal when Honda gets it together."