Daniel Ricciardo has said that Red Bull got an early start with the design of their car for 2018.
However, the former champions have caught up through the year, with Australian Ricciardo and his teammate Max Verstappen each winning a race.
"Of course, it's nice that we got better during the season," Ricciardo told Dutch broadcaster Ziggo Sport Totaal.
"But we have to make sure we are not so far behind at the start of the season.
"I feel that our starts are always a bit slow - that's certainly been the case since I started to drive for Red Bull.But a lot is going to change now. We always thought we started building the car early enough, but maybe it wasn't enough.
"That is why we started even earlier this year. Hopefully, we can fight for the title right from the first race in Melbourne. Mercedes has been winning too much and we want to change that."
Red Bull are 92 points behind second-placed Ferrari heading into this weekend's United States Grand Prix.