Mark Webber said he never had a chance to show his real pace in the Belgian Grand Prix following his poor start.
The Australian started just one place behind his Red Bull team-mate Sebastian Vettel in third, but while the German went on to dominate the race, Webber could only finish fifth having lost several positions off the line.
"The two starts we did on the formation lap and the way to the grid weren't good at all, so we had some discussion about how we could get the clutch to improve across the period before the start of the race," said Webber.
"It made it very tricky to read what was going to happen.
"When you're then out of position trying to clear people, you use the tyres a lot more.
"Then you interrogate your gear ratios. The top gear is good for free air, but with the DRS it's difficult to get the ratios right. We know free air is nice to have in this category at the moment."
Webber gained on Mercedes' Nico Rosberg in the closing laps but said passing was impossible.
"I would've sat behind Nico all day," Webber reckoned. "He was strong in sector one and we didn't have the top speed to clear him."
Red Bull tried a strategic variance with Webber and ran the hard tyre in the middle stint while most saved it to the end.
He admitted this was a roll of the dice to try to jump the Mercedes but said it made little difference.
"We had to try something," said Webber. "Two stops with prime in the middle was gambling to try to get the Mercedes.
"When you're on the back foot you've got to do something different.
"In the end track position was our Achilles heel. Pace wasn't really a problem... we didn't get to show the pace."