Lewis Hamilton believes the advantage that KERS has given him at the Italian Grand Prix will not be so great in Sunday's race.
The Kinetic Energy Recovery System played a big part in helping Hamilton grab pole position for McLaren at Monza, but the few tenths per lap benefit it delivered in qualifying will be less of a help in the main event.
With only three heavy braking zones per lap at Monza, Hamilton believes that there is not enough chance to fully charge the KERS units during a lap.
"I think in the race clearly at the start it will be an advantage, but this isn't a great place for recovering the energy," he explained. "So probably after five laps maybe you will run out of energy and then you will have to charge it up for a few laps and the same again.
"Most other circuits you can use it every single lap, and I am pretty sure here we will run out - so consistency will be a bit difficult for us. But for overtaking it will be beneficial."
Although there is heavy braking for the first and second chicanes, Hamilton's team-mate Heikki Kovalainen says that the nature of braking is not ideal for charging KERS.
"We are limited by the torque of the recovery motor rather than the braking distance," he explained. "So we are pulling very high torque under braking and that is the limiting factor.
"If we don't use it for a lap we can charge it back up, but if you don't use it 100 per cent every lap we can maintain 80 per cent every single lap. That is the sort of trade off. If you save 20 percent every lap you can use it everywhere."