The 28 year old, who had started this year as reserve driver, replaced Nick Heidfeld in the French team for the Belgian Grand Prix in August, qualifying in the top 10 three times and scoring his first world championship points in Italy last month as he picked up two for finishing in ninth.
But despite his promising start, the man from Sao Paulo is sure he can get quicker still.
"The race craft is still coming along after not racing for so long," he said. "I think I am doing OK, but I don't think I am at the racing level I was at when I was at my best in GP2.
"I think with a few more miles under my belt I will become much more competitive so I do think there is more to come.
"I have high expectations of myself and I sometimes have to remind myself that I have only done five races this season, while the others have had 15 races. I am getting better with each race and gaining experience, but I do forget that I have not done as much racing as the others."
Senna made his debut in F1 last year with the uncompetitive Hispania Racing Team where he was almost always at the back, and he has enjoyed being able to give a glimpse of what he can do with the Renault team, who are fifth in the constructors' standings.
"It has been fantastic and more than I could have dreamed of at the start of the year," he said.
"I think we have done the maximum we can in qualifying, and we scored points in Italy and generally I think it has gone well."
This weekend is a step into the unknown for Senna and the rest of F1 as they tackle the Buddh International Circuit in Greater Noida, Uttar Pradesh, which hosts the first Indian Grand Prix.
Senna saw the track for the first time yesterday and is confident he can be on the pace.
"We went around it yesterday and it looked good and I think it will suit our car. It is fast and flowing, and if we can have both our cars in the top 10 then that would be great.
"It looks like a good facility and the way it has been set up it looks like there will be good potential for overtaking with the two [drag reduction system] zones."