Valtteri Bottas says Mercedes still has to unlock more potential from its package in order to fight Ferrari in Formula 1 this season.
Bottas suggested last week that Ferrari was ahead of the pack, and while the squad had a dis-jointed opening two days to the second test – including a crash for Sebastian Vettel – the Finn maintained his thoughts on Mercedes’ opponents.
It comes after Mercedes introduced a substantial aerodynamic package for the second test, in the wake of struggling with balance issues last week.
"It is better, but if it’s enough that’s the big question mark," he said on the updated W10.
"But definitely [you can] feel improvements since last week with the stability of the car, with the overall downforce of the car, but we definitely feel we still haven’t unlocked everything there is to unlock.
"They [Ferrari] still seem strong. It’s as always from testing to Melbourne a lot of things can change, but they do have a strong package.
"We do need to unlock more from the new package to be able to really compete with them properly, still at this point I think they’re looking very strong, but there’s still a couple of weeks until Melbourne."
Bottas added: "Red Bull seems in good shape as well. I think between us two, the differences are not massive – from testing it's difficult to read in detail, but my feeling, our feeling, is Ferrari is a bit ahead of both of us.
"And honestly the whole field looks like it's a bit tighter than for example last year or the year before. It's only guessing, you never know what people bring to Melbourne."