Cyril Abiteboul believes Caterham's ability to edge ahead of Marussia is a clear indication that the team is making progress.
In the battle of the backmarkers, Caterham started this season behind Marussia who appeared to have found that something extra in the design of their 2013 car.
However, step by step Caterham have edged ahead with at least one driver outperforming the Marussias on a Saturday afternoon while in Hungary both Charles Pic and Giedo van der Garde were ahead of their nearest rivals.
It has been a similar story on race days although Marussia still hold down 10th place in the Championship by virtue of Jules Bianchi's P13 at the Malaysian Grand Prix.
"It's been an interesting first half of season for the team and for me personally. This is another great F1 season, with battles pretty much everywhere," Abiteboul said.
"As far as we're concerned, we've been fighting with Marussia who have done a great job over the last year.
"We started the season clearly behind them, but over the last three races a comfortable gap has appeared between us and them, which shows our rate of development. That's also helped us on a couple of occasions to race a Williams or a Sauber and that shows where we're setting our targets.
"This progress is positive for the whole team because it shows the aggressive development plan we have for 2013 is delivering.
"We made the decision to carry over the 2012 car to the start of this season for a number of reasons, in particular because this time last year - which is typically the time of the year when you need to produce tooling for the next season's car - the team was busy moving from one side of the UK to the other, and now we are back ahead of Marussia with the chance to reclaim tenth in the second half of the year.
"So far this performance gain has not turned into a point or an improved Championship position as this is not completely in our hands, but each time we bring new parts to the track, not only do we potentially make progress, but we also give ourselves the chance to learn more about us, our strengths and our weaknesses and to give motivation to our staff whether at the factory or at the track.
"We must not forget that we are a young group, with a limited history together, but we are growing every day."