Red Bull boss Christian Horner has backed comments from Fernando Alonso and Mark Webber questioning Pirelli's efforts in this year's Korean Grand Prix.
He reckoned that the evidence from last weekend pointed to Pirelli having been too marginal with tyre life in Korea.
Drivers were battling with high wear on their front right tyre and many - like Lewis Hamilton - found their races compromised by time lost trying to make a two-stop strategy work.
Horner, whose driver Sebastian Vettel came through the drama to triumph, suggests that the tyres could have been more durable.
"At the end of the day, we have been driving around with the same issues we had 12 months ago," he said.
"Here, the tyres were too marginal; last week [in Singapore] they were fine.
"It is a challenge meeting the different criteria of the tracks we go to, but I think this weekend the tyres arguably, while having produced a great race, were a bit too much on the limit."