Renault is confident their engines levels will be 100 percent when the season gets underway next month, but insist they will "keep some cards up their sleeves" for the remainder of the campaign.
Having been well off the pace of Mercedes last year, the French manufacturer has been working hard during the off season to catch up and provide customers Red Bull and Toro Rosso with a solid platform.
Things, though, didn't get off to the smoothest of starts in the first pre-season test at Jerez as Red Bull completed just 164 laps over four days.
However, Renault Sport F1's Remi Taffin is confident they will hit their stride soon and vowed to continue to improve during the season.
"We've definitely taken a step forward, but it remains difficult to know where we stand compared to our rivals who have also progressed, hopefully not as much as us," he told f1i.com during an exclusive interview.
"The situation will be clearer in Australia. Right now, we are not running the specifications we’ll use in Melbourne. We’re only at 80 or 90 per cent and will gradually pick up the pace and gain momentum to reach 100% by the season opener.
"Most developments will have been brought in the early stages of the season, but we’ll keep some cards up our sleeves to improve the overall package during the year."
In an attempt to catch up to Mercedes, Renault confirmed that they have made major changes.
"We’ve wiped the slate clean this year and start off on a new, solid footing," he said. "We’ve changed our methods and trackside organisation by adding a support leader in each team. The person will oversee the overall engine performance while two other technicians will run the cars.
"In order to close the gap, we had to be uncompromising, review everything that had not worked last year, and make sure to reach better efficiency in 2015. In terms of design, we’ve focused our efforts on the V6 internal combustion engine to make it more efficient, as well as the ERS to strengthen reliability. We’d already improved our level of performance at the end of last year, so our 2015 power unit is more an evolution than a revolution. Indeed, performance gains can mainly be found in the details."