Force India deputy team principal Bob Fernley says Renault has done a much better job than expected to recover from its poor 2016 F1 season.
The French manufacturer had a trying season on its return to F1 as a works outfit last year, scoring just eight points to finish ninth in the constructors' standings.
But after three races in 2017, Renault has established itself in a tight midfield pack that features Force India, Williams, Toro Rosso and Haas.
The team scored points for the first time Bahrain with Nico Hulkenberg in ninth, having narrowly missed out in Australia and China.
When asked by Motorsport.com if he was surprised by Renault's upturn in form, Fernley said: "Yes, I am. Renault have done a fantastic job over the winter, much better than I thought they would do, but we had identified that as a key issue.
"Going into testing, I felt we would be in a four-car battle with Williams, Toro Rosso and McLaren. Clearly McLaren didn't make it but Renault have stepped into where McLaren would be and I think it's going to be like that for the whole season.
"From what you can see at the moment it looks quite exciting. You've got two teams fighting at the front and four that are going to be battling for fourth place - obviously Red Bull are in the middle somewhere."
Toro Rosso's Carlos Sainz has been particularly impressed by Renault's one-lap pace, with Hulkenberg qualifying seventh in the last two grands prix, but thinks his Renault-powered team is closer in race trim.
"It looks like Renault on short run have something extra," he said. "There's something there, maybe on the aerodynamics or in the short run on the tyre or something that we don't have over one lap.
"On the long run - it looks like we look a bit similar. We are particularly good on tyres this year, surprisingly for us, in China and in Australia we were very kind on tyres, so it might be something to do with that.
"But Renault definitely have taken a huge step forward on the car side - we can see it on the data."