Fernando Alonso remains cautious about Renault's form, despite team boss Flavio Briatore's optimism following the Chinese Grand Prix.
Briatore was left upbeat about Renault's performance following the introduction of new components at the Shanghai event, where Alonso qualified in second position.
But the two-time champion admitted on Thursday he is not getting carried away, as he believes the French squad is still not ready to fight for victories or podiums.
"Not totally," said Alonso when asked if he agreed with Briatore's optimism. "Obviously we made a step forward and we are much more happy with the car now, but we know that it's not enough to fight with the quickest cars at the moment, and it's not possible to win races and maybe be on the podium.
"We know that but it's true that before we maybe lacked one second and we were in P12, P10 and now we can be much closer. I think fuel-load corrected in China we were P6 in Q3, which is much better than Australia and Malaysia, and in the race we also had a good performance.
"I started last but overtook some cars and when we were running alone maybe we were fourth/fastest, so this is definitely a good stop for us, but we know we need another one to be fighting on top."
The Spaniard said he feared Renault will have no significant updates for the start of the European season following the introduction of the new floor in China.
"I worry that there isn't (new updates)," he said. "We tried to push our new package for China because we needed it as soon as possible, but obviously when you bring a package a little bit forward you are left with nothing for the next couple of races. My understanding is that McLaren and Force India have a new package as well.
"In Barcelona most of the teams will update their cars and we will try to put some parts as well, but we need some more races to really develop the car a little bit more."
Alonso said he was surprised by Ferrari's poor start to the season, but the Renault driver reckons the Italian squad, as well as his team, will fight back as the season progresses.
"I think we all expect Ferrari to perform well in every championship. When you start the season in Australia, and you ask for the favorite you always say Ferrari because it's been the top team for the last ten years. But obviously Formula 1 is different this year.
"The cars are a little bit mixed so we need to see. I think Ferrari is a strong team, like McLaren, like Renault, and we will come back. We will improve our cars as well as be at the level of the top teams and Ferrari will do as well."