Mercedes driver Lewis Hamilton has admitted that his car did not perform well during Friday's practice sessions in Hungary.
The Englishman could not do better than a sixth-place finish in the second practice session at the Hungaroring, having come home in 13th during the first.
The 2008 world champion concedes that Red Bull hold all the cards as Sebastian Vettel went fastest in both sessions.
"We don't seem to have the pace that we had at the last race," the 28-year-old told Sky Sports News.
"Fuel loads play a huge part and when we get to qualifying we are generally able to pull out a little bit more.
"Red Bull seem particularly quick this weekend. I was told that on the same laps on the long runs that Mark Webber was eight-tenths faster at some stages, so that's interesting."
Hamilton's teammate Nico Rosberg's best result was seventh during the second practice session.