Jenson Button and Lewis Hamilton said they feel there is more to come from McLaren despite a solid start to the Singapore Grand Prix weekend.
Button emerged as the quicker of the pair in Friday practice as he set the second fastest time behind Sebastian Vettel's Red Bull, despite being slightly unhappy with the balance of his car.
However, the 2009 title winner said he was confident that the team could challenge for a fourth straight win on Sunday and felt positive about what lies ahead.
“I don't feel like I've found my flow yet – the track surface wasn't very grippy in either session because of the morning's rain,” he said. “I'm not entirely happy with the balance either – not everything we tried changing today was successful – but we've still got a few ideas for tomorrow and that's a positive.
“There's still a lot of work to do – but, if we can fine-tune the balance, we should be competitive.”
Hamilton was fifth quickest having lost time on his quickest lap when he ran wide out of the final corner onto the damp part of the circuit.
Admitting that a tight battle for pole should emerge on Saturday, Hamilton said he felt McLaren had a good base on which to build for the remainder of the weekend.
“Our car has quite a nice balance but we still need to make some further set-up changes,” he said. “It's tough in these temperatures, especially on the long runs, but to be honest I think everyone's struggling a bit too.
“In FP2, I ran a bit wide at the final corner on my fastest lap and probably lost about half a second. Still, it's great to be able to throw the car around on a high-downforce circuit.
“My race pace didn't feel great from inside the cockpit, but my engineers tell me it was quite promising. The track should also rubber-in by tomorrow, so tyre degradation should be less of an issue.
“We're in the top five, but it'll be a very tight battle for pole position tomorrow. We're looking at set-up and balance to improve our long-run pace, but today's performance isn't a bad place from which to start.”