Senna: Lack of mileage in 2009 costly

The Brazilian's main racing was in the Le Mans Series in 2009, having missed out on an F1 drive, and he has confessed that he is still paying the price now for not having kept sharp in single seaters.

"I still have a lot to improve, and I still have a lot to gain in terms of finesse," said Senna about his own performances this year. "And this is very tough to get back when you have been away for a while.

"But it is coming together and I think after a few more races I should be more competitive again. I am getting all the sectors together now. In Monaco, for example, to get all the sectors together is not easy. Hopefully in Turkey we can do it again and work on the race set-up."

Senna says that the main stumbling block in getting the most out of his HRT is in understanding where the limit of the slick tyres is.

"All the feeling for the tyres, the brake and the limit goes away a little bit if you don't race," he said. "In GP2 I was on the peak of the tyre. Right now, I am sometimes a bit under, and sometimes a bit over the limit of the tyre. And that is where the speed really comes from. It is just about being on the limit, not over or under it.

"Right now I am being on the limit of the tyres for 75-85 per cent of the time. I know I can be there 95 per cent of the time, and only driving around can get me there. I just need a few more miles."