Renault set themselves the target of closing the gap with the top three teams as they unveiled their 2019 car at their Oxfordshire factory.
The French company finished fourth last season, after coming ninth in the first year of their return in 2016 and sixth in 2017.
Team boss Cyril Abiteboul said: “We want to fight for more. We know it will take time.
“This year is consolidation. We want to reduce the gap to the frontrunners.”
Former Red Bull driver Daniel Ricciardo joins Nico Hulkenberg for 2019.
Ricciardo, who won two races for Red Bull in 2018, said: “It was a big decision for me and it certainly shook up a little bit of F1 and had quite a ripple effect on the grid. My intention wasn’t to do that. I was looking out for myself and I felt this was the right place for me for the next chapter of my career.
“The ambition is there – from ninth to sixth to fourth says it in itself – but there is no sense of complacency; there is big excitement and that motivates me.”
Abiteboul added: “We have the drivers. Then we want to target engine excellence, while we give a bit of time to (the factory at) Enstone to deliver a race-winning chassis.”
Renault said there had been substantial progress on the engine, a weakness in recent years.
Engine boss Remi Taffin said it had been the “best winter for the last five years”, since the introduction of turbo hybrid engines in 2014.