Solaris Bus & Coach has delivered the first units of the enhanced, second generation Urbino 18 Hybrid city bus. It uses a smaller diesel engine, resulting in lower fuel consumption and better operating efficiency. The first of the new Solaris hybrid buses have been handed over to customers in Bremen and Hannover. Further Solaris Urbino 18 Hybrid for customers in Germany and Poland will follow later in 2008.

Two years after the premiere of the Solaris Urbino 18 Hybrid, Solaris Bus & Coach has significantly enhanced the drive train of the environmentally-friendly hybrid bus. It now uses a smaller diesel engine, which is aided in its work by the electric engines of the hybrid system. Offering 178 kW at 6.7 l capacity, the new diesel engine is even more fuel-efficient.

Independent tests carried out by the TÜV SÜD group in Prague confirmed that the new hybrids have a fuel consumption which is almost 24% lower than on comparable conventional diesel buses. The hybrid bus now uses the 178 kW (242 PS) Cummins ISBe5 250B engine. At 6.7 l capacity, it produces 1005 Nm torque and meets the demanding Euro 5 emissions standard. The second-generation Solaris hybrid bus uses 23.8% less fuel in the SORT1 cycle. Savings in SORT2 are 23.4% and in SORT3 22.9% less fuel is consumed. However,  the most important fact is that a lower fuel consumption means lower emissions and less of a strain on the environment.

The hybrid system continues to be the EP system from Allison Transmission. At 2×75 kW, its electric engines provide the same power as in the first generation of the Solaris hybrid bus. However, the system has been further optimised  to match the performance of the new diesel engine. As before, energy recuperated from braking is stored in roof-mounted nickel-metal hydride batteries. In the second-generation Solaris Urbino 18 Hybrid, the drive train is located at the rear of the bus as on the standard diesel version. The engine is mounted vertically, while the hybrid unit takes the place of a conventional automatic gearbox. Power is transmitted to the rear axle.

With further components of the hybrid system such as batteries and the Dual Power  Inverter Module placed on the roof, the saloon layout is the same as on the conventional diesel version of the Urbino 18. The first second-generation Solaris Urbino 18 Hybrid has meanwhile been presented to its customer, Bremer Straßenbahn AG of Bremen.