The problem can be solved in 2 ways. Both ways however, involves
the use of a drop centre axle. This reduces axle space penetration
into the pax compartment. Now heres the differences among the 2
ways:
1st way : You can use a horizontal piston-ed engine, like the
O405, the O500LE and B10BLE and B10M alike. This reduces engine
space compartment needed for vertical engines, therefore permitting
a lower floor. With a special layout of the chassis, the
combination can be made into a low floor bus , not low entry.
2nd way : Even with a vertical engine, you can still make the
bus low floor, just place the engine in a transverse position, like
the CRBs, B10TLs.
fyi, B10M cannot be low-floor due to the mid-mounted engine,
which resulted in the high high bodywork and floorboard.