Sebastian Vettel says he was relieved to learn that a chassis fault could have held him back in recent races.
The German was outpaced by his Red Bull teammate Mark Webber in both Spain and Monaco, as the Australian took back-to-back victories and joined Vettel on equal points at the head of the championship, while the latter had to settle for third and second places in the two events.
Vettel has been given a different chassis for this weekend's Turkish Grand Prix, with Red Bull having discovered a problem with his previous car following Monte Carlo. He admitted he had found it hard to understand why he was struggling to match Webber.
"It can't be an advantage," Vettel said when asked about the effect of the chassis issue on his pace. "I wasn't happy for the last two races. If you look at the last race in particular – especially after the safety car period and at the start of the race – at some points he [Webber] was one second per lap quicker. Fortunately, Monaco is not a place to overtake, but I was struggling to keep Robert [Kubica] behind me.
"I was complaining for the last couple of races that something was not feeling right, and it was good on Sunday night when we decided to change the chassis anyway, just to make a change and find something. I think it explains a lot. On top of that, we also found other things that weren't in proper shape."
He felt the disparity between the two Red Bull drivers' performances proved that something was not right with his car – although he acknowledged that Webber had performed very well.
"Whereas he always seemed to be quite happy, I wasn't," Vettel said. "But I think he did a very good job."
He warned that he was not expecting to automatically gain the upper hand now he had a fresh chassis.
"It doesn't mean we'll come here and everything is solved," said Vettel. "We still have to work hard and try our best to be at the front again."
Webber currently officially heads the championship by tiebreaker, having won two races this year to Vettel's sole victory in Malaysia. Vettel said he was pleased to still be in such a strong position given his early season reliability issues and the recent chassis issue.
"There are a lot of races still to come," he said. "Even in the races we were struggling a little bit, we still got the maximum out of it and we still saved a lot of points."