Mark Webber believes the McLaren team was not showing its real pace in Friday's practice for the Spanish Grand Prix.
Although Lewis Hamilton and Jenson Button topped the first session, it was the Red Bulls of Sebastian Vettel and Webber who dominated the afternoon, with Vettel nearly a full second quicker than the first non-Red Bull car.
However, Webber reckons there is more to come from its rivals, the Australian reckoning McLaren was hiding its true speed.
"I haven't particular seen a huge amount of what has happened in that session, but for sure McLaren probably weren't showing everything today," Webber said.
The Red Bull driver, second quickest, was still pleased with his day's work after a smooth session.
"Yeah, certainly a smooth one from both sides of the garage," said Webber. "That is a nice positive for the team. They have done a huge amount of work over the last few months, as all the teams have.
"Particularly last night, the guys worked like hell, very, very late night for our team and the boys deserve a smooth Friday. We have some stuff to go through tonight and hopefully will be well prepared for tomorrow."
He added: "It was a good day. We had a smooth run and nice to have a good P1 and P2 with no interruptions from the weather. The guys worked faultlessly in the garage, the driver did a little bit of his work as well and it was a good day for us."