He scored some solid points at the United States GP, but Jenson Button admits he thought McLaren would be a bit faster.
Button started Sunday's race at the Circuit of the Americas in 11th place while his team-mate Fernando Alonso, who ran an upgraded Honda engine, was two places ahead of him on the grid.
Both found themselves inside the top 10 for most of the race and, although Alonso failed to score any points after he suffered a loss of power late on, Button managed to finish sixth, which is his best position of a miserable 2015 season.
However, both McLarens were unable to keep up with the likes of Max Verstappen and Carlos Sainz from Toro Rosso and the 2009 World Champion says he was hoping the MP4-30 would have a bit more speed.
"Our pace was nowhere near what we expected here," he is quoted as saying by Motorsport.com. "So compared to like Toro Rosso, they were so much faster, a lot faster than I expected round here, and especially in the mid-high speed corners I thought we'd be stronger, but we are not.
"So we need to look away and look at why. A tough day, but I'm happy to get sixth place.
"I think we did a good job with that, but apart from that, the pace of the car was not that exciting."
Alonso was forced to make an early stop after picking up a puncture at the start, but he recovered to fifth before he lost power.
"We would have finished fifth and it would have been one of the best races of my career," the Spaniard said. "And I'm still considering it that, but with a result out of the points.
"I leave with the feeling of having done my best race in several years and hopefully I can repeat it in the three that we have left."