Renault have made some progress in ironing out the engine problems that have blighted Formula One preseason testing, but will head into the season-opener in Melbourne with doubts about their incomplete preparations.
Renault supplies champions Red Bull, Toro Rosso, Caterham and Lotus, and the performance of their new engine has disappointed at the tests in Jerez and Bahrain.
All up Renault-powered cars have completed less than half the total kilometres of the four Mercedes-powered teams.
Renault were also considerably slower, with four-times world champion Sebastian Vettel's fastest time on Sunday's final day of pre-season testing over four seconds slower than table-topping Lewis Hamilton's best with Mercedes.
Formula One has undergone a major change with the introduction of a new turbocharged V6 engine and energy recovery systems.
Renault Sport Formula One's deputy managing director Rob White says having not completed the entire testing programme they can't escape the fact their preparations for the Melbourne Grand Prix are incomplete.
On the upside though he maintains they've done some of everything, with simulations of qualifying sessions, starts, race distances and long stints and believes they have made progress.
