The Japanese racer ended the first Bahrain F1 test with a best lap of 1m39.8s, which is four tenths of a second slower than last year's GP2 pole at the same circuit for 2013 champion Fabio Leimer.
While most Renault-powered teams are focusing on making their cars reliable at the moment, Kobayashi is keen to help Caterham find some more speed at next week's final pre-season test.
"We are not in race conditions here, but if we were in race conditions I think I should bring a GP2 car," Kobayashi told reporters in Bahrain.
"The lap time is still quicker in GP2. We need to work, but in this moment if we were to race, I think it's not Formula 1.
"When you look at the lap time, I need to be worried. I cannot be happy, but I have to think about what we can do.
"Time is very limited, and we need to think about reliability, but also performance. We have to try as much as we can."
F1 2014 is not too slow
The ex-Toyota and Sauber man added that he is not particularly interested in having to rely purely on reliability for Caterham to land more competitive results than it has experienced so far in F1.
When asked by AUTOSPORT if a slow car that was reliable could enable the team to score its first points, Kobayashi said: "I am not looking for that.
"I'm looking more for the potential for us to catch up. This is the most important part of why I am here.
"I'm not just thinking about finishing the race, of course I also need performance.
"This year is the biggest chance for this team.
"There is a lot of chance and possibility, but at the moment we are a little bit off the pace compared with the other teams on the development side."