Has something to do with acceleration between the Citaros &
KUBs from what I can tell. For example, for the set of bus stops
along Pasir Ris, it might take up till 2 mins to get from one stop
to another in a KUB with full acceleration. But in a Citaro under
full acceleration, the time taken is usually about 30s or 45s
lesser on average. This is what I observed because I take 53 at the
same timing every weekday in the morning and more than twice weekly
the same BC would be driving the slot, just that his bus alternates
between 6035L/6036J and same random SP KUB. The traffic conditions
at that peak hour time is usually similar too.
The KUBs (more so the Euro Vs) have a more sluggish gearbox if
you could call it. The BCs can floor the Euro IV KUBs in almost the
same manner as you would in a Citaro, but do the same in a Euro V
and the gearbox will just simply refuse to shift up, then cause the
whole bus to have a big jerk and losing speed before it finally
upshifts.
Probably that's why there's like more Euro V KUBs as SPs then
the Euro IVs in recent months, those Euro Vs are definitely not
kicked out by having a higher mileage than the Euro IVs in any
case.
Seriously, there's no reason to floor accelerator each n every
time, engine will wear off in the long run...
in fact, contary to what people believe, if you keep on 'drag'
your gear, the gear will tend not to change at all. It's like why
MT vehicles you've to apply cluch and let go of accelerator to
change gear.
It's all to do w/ smooth driving that let your pick up be
faster.