Defending drivers world champion Sebastian Vettel has told his Red Bull team it is 'time to think again' about why they are losing races after finishing second behind Jenson Button's McLaren in Sunday's Hungarian Grand Prix. The 24-year-old German, who extended his runaway lead at the head of the drivers' standings despite the result, made it clear he is concerned about his team's drop-off in form after one win in five races. He has now gone three without a win after winning five of the opening six this year. But he retains an 83-points lead in the title race ahead of his Red Bull team-mate Mark Webber. Vettel said: "We tried to win, there had been a chance, but we didn't use it. We need to look into that. We've seen how quickly things can change so we need to win again. "And I think it is fair to say that in the last couple of events Ferrari and McLaren, on race pace, have made a step forwards. We need to have a look at why. Maybe it is something they have done, yes. "But we also need to have a look at ourselves. "There is plenty of stuff to learn and things that we can improve without looking at the others. That has to be a target for the next race and for the second half of the season. "I felt the pace was in the car, especially after last week (in Germany). I think we made a good step forward and I felt much more comfortable, but I start the race to win and not to finish second or third. I think we could have been a bit smarter. "With so many races you have to be prepared and you shouldn't be surprised if you face some difficult races. But the target for the next race is to attack completely and try to win again." Some of that extra comfort came thanks to the team using their first 'curfew-breaker' and working through the night on Friday to find an improved set up for the champion. Teams are allowed only four curfew-breaking shifts each season - that is to say work in the curfew hours of 2am to 8am. Vettel started from pole, but in changeable conditions he could not cope with the superior performance firstly of Briton Lewis Hamilton and later from his compatriot Button as the two McLaren men demonstrated their greater speed. The champion's three-stop strategy, including a final stint on the harder 'prime' tyres, rescued second place for him. But, referring to his strategy, he added: "Both times (coming in) a lap earlier would have helped us a bit -- it would have given us a bit more time. I felt the pace was there on the last stint, I had some issues with brakes and Jenson wasn't slow either. "So, after all of this, I have to say I am not 100 per cent happy -- I started from pole and I had a feeling that I could have won the race, pace-wise it was not impossible. It was a difficult one with the conditions but the target is to win and not to come second. Still I know they were good points today. "There are still many races to go so our target has to be to win. We still feel hungry to win races, full stop." That hunger, allied to his luxurious lead, is virtually certain to see him take a second successive drivers title before his 25th birthday, but it may not be enough to prevent a shift of power in the future. On the evidence of recent races, both Ferrari and McLaren have shown their strength in depth and their speed - and an ability to beat the Red Bulls in race conditions. As Vettel has said, it is time for his team to take a re-think as F1 heads into its annual summer holiday when every team must close its factory and stop work for two weeks before the next race, at Spa-Francorchamps, in Belgium at the end of the month.