The expected results in terms of fuel savings of 10 to 30 percent were only partially achieved by the hybrid buses. In the case of the MAN bus, fuel savings of around 20 percent compared to a conventional diesel bus can be achieved. A clear statement on fuel savings in the case of the Mercedes-Benz hybrid bus cannot yet be made, as it has so far only been in use for six months, which is too short a period.
The technical condition of the Solaris bus is stable, although the brake system requires improvement: the operating brake pressure needs to be increased for calculating the minimum braking ratio. In the case of the MAN bus, there are frequent malfunctions to report. Frequent problems are also noticed with the Mercedes-Benz vehicle, which are largely caused by not yet fully developed software. The system comparison of the different hybrid technologies in respect to environmental aspects and economic efficiency and the analysis of fuel savings commenced on 13 April 2011, when the third bus went into operation. Here too, the period to date is too short in order to make any reliable statements.