Jenson Button described his Indian Grand Prix qualifying session as "terrible" and admitted he was puzzled by how his McLaren's performance had changed since practice.
The Briton was 0.7sec off the pace in fifth place at the end of Q3, though he will start fourth once his teammate Lewis Hamilton drops from second to fifth due to a gearbox change penalty.
Asked if he was happy with his car's performance in qualifying, Button replied: "No, not at all. This morning the car felt great, the pace was good and the car just felt good. This afternoon I just couldn't find any grip, on the prime tire, especially. I didn't really get a clear lap either on either of my soft-tire runs. The traffic's been terrible out there."
He said the McLaren had felt more competitive in race trim in practice and hopes that remains the case on Sunday.
"At the moment I've got to work out why I can't find a better balance, and then hopefully we'll have a better race than qualifying because it was a disaster in qualifying really," said Button. "The car felt good on high fuel yesterday and I'm hoping that we have that balance tomorrow."
Button's best time in qualifying came just as Felipe Massa crashed in the final sector. The McLaren driver felt he had done all he could to acknowledge the yellow flags for the incident, that he passed as it unfolded.
"He was heading into the gravel as I was coming up to it," Button explained. "I saw the tire marks, I saw the smoke and then I saw the yellow flag, but I was actually in the yellow flag zone already so we'll see what happens, but I backed off."