Narain Karthikeyan says he needs to improve on his qualifying performance through the second half of the F1 season.

The Indian driver has failed to qualify higher than team-mate Pedro de la Rosa in any session so far this season, although his performances on race day have been more encouraging, even though HRT remains a long way from scoring points.

Speaking in a Q&A released by the team, Karthikeyan insisted that he was pleased with his race displays so far but wanted to get closer to the pace shown by de la Rosa in qualifying - with lack of knowledge of the Pirelli tyres compared to the Spaniard working against him.

"I think that my race performance has been very strong, with my 15th place in Monaco standing out, but in qualifying I've been a bit weaker," he said. "Right now I'm about three tenths behind Pedro and that's something I have to improve in this second half, no doubt about it.

"The tyres have been quite difficult to get used to and Pedro has a lot of experience with Pirelli and McLaren. He's a very good driver who hardly makes mistakes and I must learn from him to improve."

Karthikeyan added that his performance in qualifying was holding him back when it comes to giving himself a mark for the season so far.

"We all know that the start should have been better in normal circumstances, but with the changes that had to be made and other things we inherited, it wasn't possible," he said. "To make it to Australia with the car on time was an achievement in itself. We've moved on from that and have progressed a lot. For now I give myself a 6 or a 7, and if I improve my results in qualifying, then an 8 or a 9.

"From where we are now, it would be great to match and beat my team-mate Pedro who has been a good benchmark. Added to that, if we finish ahead of Marussia in the championship standings that would be a successful season."