Adrian Sutil says the final test day at Barcelona tomorrow will be a critical one for Force India as it runs its Kinetic Energy Recovery System (KERS) for the first time.
The team launched its latest car a week later than most, and held off using 2011 additions such as KERS and the adjustable rear wing at its maiden test at Jerez. It will now try Mercedes' KERS for the first time at Catalunya tomorrow. Sutil said that the VJM04 was currently performing well, so it was important that KERS added performance, not complications.
"You always concentrate on performance but there's still a lot to come," he said of testing so far. The balance now is OK, but we'll run the KERS and the KERS affects the balance quite a lot, so that's why we really have to wait for that before we can say where we are. Tomorrow, hopefully we'll get it on and maybe I'll know more about how it really feels after that one."
He said he was optimistic at present, as he has been impressed with the new Force India so far and the Mercedes KERS was well regarded when it was last used in Formula 1 in 2009.
Asked how significant to Force India's program the first run of KERS would be, Sutil replied: "It's very important, of course. But I think we have a good package. Mercedes KERS is well known as the best KERS so I've no concerns that it should make any problems. We'll fit it in and see how it goes."
Today's test ran more smoothly for Force India than some of its preseason days so far, and Sutil was pleased that he was now getting enough mileage to make good progress with the new car.
"There were a few problems at Jerez but my days were quite good," he said. "For me it's the second day of good driving in the car."