The vertically mounted 6871 cc D 0836 LOH Euro 6 is offered with
either the 250 hp or 290 hp output and is only available on the
European spec Lion's City. Vertically mounted means that the engine
is installed vertically, which allows the 3rd door to be
installed.
The 10518 cc D 2066 LUH engine however is horizontally mounted,
and the engine is installed horizontally, which means that there is
no space for the 3rd door to be installed.
That is incorrect.
Regardless of the engine installed, Lion's City can accomodate a
3rd door on the right.
The D0836LOH is only availble in an engine + radiator tower
configuration which is similar to the new Citaro C2 Euro 6. MAN
markets this chassis type as A37, and this is now shared with the
Lion's City Hybrid which uses the same engine with an added electic
motor.
The A37 will look like this internally due to the engine
tower:

On the other hand, the normal Lion's city with D2066LUH engines
are also available with a 3rd door, marketed as A21. This config is
less favorable (but widely used) across europe due to a very high
platform opposite the 3rd door where the engine is located.
