Barrichello reserves judgement on engine

The Japanese squad are aiming to steal a march on their rivals by racing with the 2007-spec engine at next week's Italian Grand Prix, ahead of F1's planned engine freeze.

Next year's engines have to be lodged with the FIA after the Chinese Grand Prix, and Honda are hoping to benefit from using it in Italy, the previous race, to fine-tune it.

Barrichello tested the power unit on Wednesday, completing 71 laps on his way to the ninth fastest time of the day.

The Honda driver, however, said it was too early to judge its performance.

"It is very hard to say on this track," Barrichello told autosport.com about the performance of the engine.

"It's not too fair to judge it here, but in terms of power I did not feel much difference, and in terms of characteristics, it is such a stop and go track and you feel the loss of power most on this track.

"We have to run more to see, but it is very difficult to judge here."

Barrichello's engine, which had been used since the first day of the Monza test, expired this morning after over 1,200kms.