Lance Stroll has admitted that Williams needs "time" to get the most from its 2018 car.
Once a stronger force behind the top three teams, the British outfit had a less competitive winter with its new car and young driver lineup of Stroll and rookie Sergey Sirotkin.
"The design of the new car is more daring, and it will take a little more time to get the most out of it," Stroll told Canadian newspaper La Presse.
"The car is already better than last year's, but that's the same for everyone. We'll only know in Melbourne where we are."
Stroll, still 19, is often dismissed as a 'pay driver', and he admitted that it is "true" that he struggled at times last year alongside Felipe Massa.
"But I feel much better in the car now and, with experience, I think I can be much faster," he said.
"It's hard to do well in qualifying when, like me last year, the day ends in Q1 or Q2. It's hard to get used to the tyres and find the limit of the car when you only have one or two laps to do it.
"But I now know more about what to expect, so I think I can do a lot better in qualifying."
Stroll also said that he has learned a lot about setting up the car and finding a good balance, and is therefore ready to be the most experienced Williams driver.
"Sergey and I have a very experienced team around us, and I'm very comfortable in the team. I know all the circuits and the routine.
"I will do my best, and I don't see why I will not have a better season than the last. What remains to be seen is if the car will be competitive."
The Australian Grand Prix gets the 2018 championship underway on Sunday.
