Renault is still "about a month" behind its rival F1 engine suppliers.
That is the admission of the French marque's Remi Taffin, despite the fact premier partner team Red Bull has taken a big step forwards in Melbourne after a disastrous winter.
"This (Mercedes and Ferrari's level) is what we wanted, and what we imagined we would achieve.
"We're not there yet, because we've had reliability problems and that caused a bit of a delay. We are about a month behind," said Taffin.
And Mercedes' F1 chairman Niki Lauda said no engine supplier is currently giving full power to its customers.
"Not even Mercedes," he told Kleine Zeitung newspaper.