Vitaly Petrov hopes that Renault has solved the braking issues that have plagued him during his two days of testing at Jerez this week.
The Russian had a spin on each of his two days in the car, which he put down to struggles with the car's KERS unit. But he is optimistic that he will be able to focus on general setup work next week at Barcelona after making changes toward the end of Friday's running.
"We found some good things on the brakes, which is very important for me," said Petrov. "It is my first time using the KERS, so we spent a lot of time working on this area.
"It was very difficult to find the right setup. With KERS it is very different than last year; when you first hit the brakes, the rear is locking straight away.
"We pushed and went the right way with this all day, and in the last minute we went out and I was checking the brakes. Now I hope it works for Barcelona."
Renault had planned to do a full race distance run this afternoon, but the team lost time due to what Petrov described as a "fluid leak." However, he was pleased with the amount of work carried out over his two days in the car.
"It was positive for us, we sorted out a lot of problems and understood a lot about the car," he added. "In Barcelona I think we can do some proper tests."