Daniel Ricciardo says he was surprised by the lack of grip at the Autodromo Hermanos Rodriquez circuit during Friday practice for the Mexican Grand Prix.
The Australian was the quickest Red Bull driver on Friday in Mexico, finishing eighth in FP1 and fifth in FP2, but could only get within 0.658s of Sebastian Vettel's fastest time in the afternoon session. Ricciardo admits he expected to find more grip after a number of races at the track since last year's grand prix -- including the World Endurance Championship and Formula E, which ran on a modified layout.
"I think it will get better, to be honest today I expected the grip to be higher after a year and the WEC came here and other categories," Ricciardo said. "I thought the track would have rubbered in a bit, but it's still very slippery so it might take a bit more time.
"I think by the end of the weekend on Sunday the last half of the race will be better, but I think we're going to be fighting the balance from now until the end, it's just trying to get comfortable with a slippery sort of feeling on track."
Ricciardo says the lack of grip has made finding the right set-up difficult but he remains confident that Red Bull will be able to discover a solution ahead of Sunday's race.
"It's really tricky to actually find the right setup in these conditions, when it's low grip you have a bit of understeer and you have a bit of oversteer, so knowing what way to really set the car up is tricky.
"I think we improved it today from the morning but I think there's still some progress to make, so we'll prepare for a pretty low grip track tomorrow and try and improve the balance from there."
A number of drivers complained of high tyre degradation during both sessions, particularly on the super-soft tyre. Although he struggled himself on the softest compound during long runs, Ricciardo feels Red Bull has more pace to find over one lap ahead of qualifying.
"I think the super-soft on one lap will be quicker, but on the long run it was not lasting very long today. For a lot of us we had problems with that tyre, so I don't think we'll do many laps on that tyre on Sunday, we'll see what happens."