Valtteri Bottas thinks Williams is making progress in solving the weakness it has had in slow-speed corners over the past few seasons.
Williams has finished third for two years in a row but has been unable to claim a victory in that time. Slow-speed corners have been an issue on successive Williams cars, which have also been poor on tyres and lacking performance in the wet.
Asked if he had seen an improvement in the FW38 through slow corners, Bottas said: "I think we are. We had quite a different programme today compared to last week, so that's why the times are better. We're making progress all the time, we're learning about out new car and what kind of set-up it needs with long runs, short runs."
Though Bottas thinks world champions Mercedes will be in a league of its own again in 2016 he is also quietly confident Williams can expect a more competitive season.
"What I've felt so far is progress from last year, but it's so difficult to say in fine detail where we are, although definitely Mercedes is looking strong. I do hope we can fight with Ferrari and Red Bull, and we will see. It's going to be a competitive season. I just really hope we can be up there fighting for the places we want."