Here is what I would specify for Singapore.
Model: Mercedes-Benz Citaro²
Engine: Mercedes-Benz OM 936 h (EURO VI) with
twin-stage turbocharging, 260kW/354hp @ 2200rpm, 1400Nm @
1200-1600rpm. Alternatively, Mercedes-Benz OM 470 (EURO VI)
with asymetric turbocharging, 265kW/360hp @ 1800rpm, 1700Nm @
1100rpm.
Transmision: Voith DIWA 864.6 SensoTop, 5.77:1
final drive ratio with ZF AV 132 driving axle and 275/70 R22.5
tyres - oad speed at rated engine speed in top gear is 91km/h (OM
936 h) or 75km/h (OM 470). Alternatively, ZF-EcoLife 6 AP
1700 B TopoDyn (OM 936 h) or ZF-EcoLife 6 AP 2000 B TopoDyn (OM
470), 5.77:1 final drive ratio with ZF AV 132 driving axle and
275/70 R22.5 tyres - road speed at rated engine speed in top gear
is 108km/h (OM 936 h) or 88km/h (OM 470).
Passenger configuration: 2 doors, 39 seats
(largest seating capacity), wheelchair bay opposite rear door with
folding seats and ramp request button, electric wheelchair
driver-operated ramp fitted under rear door, glide-away doors front
and rear.
Other: Mobitec LED destination equipment
(front/centre with route number and destination, rear with route
number only), heavy-duty air conditioning, ISRI driver's seat,
driver's area air conditioning booster, driver's lock box.
REASONING
I went with Mercedes-Benz because I feel that they offer the
most attractive product for most applications. Engine
selections are the best compromises between economy and performance
in an environment that demands strong acceleration. Voith is
the preferred gearbox due to lower number of gearchanges in a dense
urban environment with low average road speeds with no requirement
for high road speeds. Taller final drive ratio (as opposed to
6.21:1) selected for improved passenger comfort and increased fuel
economy due to lower engine speed averages.and longer intervals
between gearchanges, also resulting in lower exterior noise
levels. Heavy-duty air conditioning option is a requirement
for Singapore, as is the driver's cab air conditioning
booster. Electric wheelchair ramp is another feature that
would greatly improve the passenger experience.