Jarno Trulli says his issues with Lotus' power steering have been improved by modifications introduced for Turkey, but that the problem is not totally resolved yet.
The Italian joked that the revised system seem to have passed the problems onto his team-mate Heikki Kovalainen.
"It's funny, because I feel that it is a little step forward but it doesn't now seem to be making Heikki very happy!" Trulli told AUTOSPORT.
"You can see sometimes how changing things can affect one driver more than the other. From the data, we can see that it is slightly better but it's not the way it should be."
Asked if the changes made the steering more consistent, Trulli replied: "No, I still have some work to do. We solved some friction problems because we did have some friction problems in the steering column, but we need to work on the steering feedback. I have always struggled with that."
Trulli underlined that he was generally happy with the car apart from the steering issue.
"What I said when I jumped out of the car today was that the car has got a lot of potential which, at the moment, I struggle to extract because of this power steering problem," he said.
"I don't have the confidence to attack. But the car seems pretty good. It has got a lot of grip and seems pretty competitive.
"There is at least half a second in the car that I cannot get out at the moment. The way that the team is developing at the moment is pretty good."
He does not think Lotus will be making any great strides forward this weekend, but that it will be snapping at the heels of the more established teams ahead.
"We are very close to the midfield, so anything can happen," Trulli said.
"If we can get everything together and get the weekend right we can race with them. Maybe we will be at the bottom of the list but still very close.
"Maybe we can get an advantage if they have trouble or don't get it right. We have made quite a step compared to the people behind us."