Michael Schumacher says Red Bull are driving in a league of their own ahead of this weekend's Turkish Grand Prix.
Red Bull's Mark Webber has won the last two races and the team holds a sizeable pace advantage over their rivals.
Mercedes driver Schumacher said: "When you see the position we are in, Red Bull are driving in their own world.
"After that it's Ferrari, McLaren, Renault and ourselves but I hope our development moves us closer to be in a reasonable position to fight."
Red Bull have arrived in Turkey with another major update to the peerless RB6 and the team are expecting a step up in performance similar to the one they experienced in Barcelona three weeks ago.
Among their new parts is Red Bull's version of the 'F-duct' aerodynamic device pioneered by McLaren this year which improves straight-line speed.
The aerodynamic overhaul they unveiled in Spain helped them outpace their closest rival, McLaren's Lewis Hamilton, by 0.8 seconds in qualifying and Webber claimed an impressive pillar-to-post victory.
Yet more refinements to the car would appear ominous for their closest rivals and McLaren's Jenson Button and Ferrari's Fernando Alonso said they shared Schumacher's thoughts about Red Bull's supremacy.
"If you look at the last two races, there's been one team that's really stood out and that's been the Red Bull," said Button. "So it's about chasing them down.
"Coming here I think we can challenge other teams but Red Bull is a standalone team and has been over the last few races.
"We have to hope our improvements have moved us closer to them and that's all we can hope for at the moment."
Alonso, who won the opening race in Bahrain and finished second in Spain, added: "It's the feeling we all have.
"Red Bull were one second ahead in Barcelona and there will be no magical surprises here.
"They are clearly ahead of everyone and are leading both championships so it's up to us to catch Red Bull as soon as possible.
"Hopefully, in Canada, Valencia or the next race but maybe not here in Turkey. From Barcelona to here it is only three weeks and it is impossible to cut out that one second advantage."
However, Webber, who leads the standings on the same number of points as his team-mate Sebastian Vettel, and is three points ahead of third-placed Alonso, expects the other teams to provide a stern challenge at Istanbul Park.
"We were competitive in Barcelona but I think it will be hard to do that again," said the Australian.
"Venue to venue things are moving around but we are working incredibly hard.
"Results in the last few weeks have been rewarding because we've had missed opportunities in the past.
"We saw last year that cars that were flying at the start of the year slowed down and were exposed by the end of the season, so we're conscious of that."
Vettel arrives in Turkey with a different chassis after he complained about handling errors during the race in Monaco, where he finished second.
A post-race inspection found an "unspecified flaw" and the chassis has been substituted for the one he used during pre-season testing.
"I wasn't happy in the last two races," said Vettel, who sealed a dominant one-two for Red Bull in Monaco.
"It's difficult to say [if it will make a difference]. It explains a lot."
Webber is expecting fierce competition from Vettel, who he only leads in the championship by virtue of having won two races to his team-mate's one.
"Clearly Sebastian is in a good car and very quick," Webber continued. "But he's had his day when he's untouchable. It's no secret we like to beat each other, but it's a healthy competition, a good battle."