BMW’s KERS not as good as Mercedes’

(GMM) BMW-Sauber's KERS system is not living up to the Swiss based squad's expectations, the publication Motorsport Aktuell reports.

The German team has had a difficult start to the 2009 season, despite championing the energy re-use technology and marking the words 'Active Hybrid' on the rear wing of the F1.09.

Only Nick Heidfeld has consistently used the system so far, reportedly because BMW's system is much heavier than for example the leading McLaren-Mercedes KERS package.

"I don't know whether the systems of our competitors are heavier," Mercedes' Norbert Haug is quoted as saying by spox.com, "but if ours weighed 10 kilos more, we probably would not use it."

It is also believed that while the 82hp power bursts are available to McLaren drivers for the full allowed 6.6 seconds per lap, the same is not always true of the BMW KERS.

BMW team boss Mario Theissen acknowledged to Germany's Auto Motor und Sport: "It depends on how many braking zones there are, in terms of charging the batteries.

"With our system, we are on the limit with certain circuits," he added.