Lewis Hamilton admits he will be "in trouble" at Sunday's British Grand Prix if he fails to get more out of his car in the build-up to the race.
The defending World Champion has been slow out of the blocks at Silverstone as he was P2 behind Nico Rosberg in FP1 while he was only down in fourth in the second session and was 0.466s off his Mercedes team-mate's time of 1:34.155.
Hamilton struggled throughout FP2 and he barely had a race simulation run before he told the team that his car was "all over the place right now and I can't go any faster".
He ended the session not only behind Rosberg, but also the two Ferraris of Kimi Raikkonen and Sebastian Vettel.
Asked after practice how much more there was to come, he replied: "Hopefully there's a lot, because, if not, then we're in trouble! The car wasn't feeling bad today so it's going to be close as the Ferraris look like they should be closer. It should be a good race."
He added: "Not the easiest of days but it's generally been okay. The long run pace was not so great, we definitely have decent pace we've just got a bit of work to do on the setup but otherwise we're good.
"I've not really got to sit down to do the maps to look whereabouts it is but it's a general balance thing that we've got to get right."
The Brit had some problems with his clutch in Austria last time out, but he has opted for a different set-up at Silverstone.
"I've gone back on clutch set-up which feels really good so far – just like it did in the first few races. So, overall, it's looking like a positive start," he said.