I was travelling on a new generation M-B (suspect to be IBC
1725) using MTrans coachwork via Transtar 1st Class & seated
such that i could observe the readings from the instrumentation
& driver behaviour etc.
As this is still very new bus chassi (mileage only 35000 km then)
& under warranty, i have been told by another operator that the
original settings as specified by the maker are not tampered with
(yet perhaps !), which likely explains why i noted the tachometer
needle could not exceed 2500 rpm, the start of the red zone for
this model. The coach driver even showed his frustraution to the
lady coach attendant on board by repeatedly pointing his finger @
the red zone beyond 2500 rpm grumbling something that they set the
engine speed limit @ 'only' 2500 rpm mark & as such he could
not drive faster then 120 km/h ! So of course for much of our
journey from SGP to KL which lasted just over 4 hours nett driving
time, i noted 120 km/h was shown on the speedometer & 2500 rpm
on the tacho. I've no real reason to suspect the indications are
inaccurate since the vehicle is still in brand-new condition &
also due to what i've been told above. I've also riden in numerous
not so new but older models of M-B & Scanias etc. & noted
similar road speeds corresponded with similar engine speeds &
of course the travelling time to cover roughly the same route was
also similar ! That's another reasons why i do believe the readings
on the gauges are reasonably accurate.
Shorthly before he was saying all that, we were overtaken by
another M-B, the twin-exhaust piped OH 1627 L. I've riden this
model many times & have seen the tachometer go well into the
red zone, meaning little higher than 2500 rpm with the
corresponding road speed around 130 km/h, which is maintained much
of the time throughout my journeys ! I believe why our driver was
grumblling afterwards was because he wants the engine speed
limitation removed so that he could drive 'like the rest' i.e. well
into the red zone so as to get the 130+ km/h road speed too so he
won't 'lose out' !
I've also riden on the older Hino chassi before & noted road
speeds ~ 135 km/h with corresponding engine speeds ~ 2600 rpm, of
course well inside red zone.
So you see, what i've mentioned are based on what i've actually
seen on my many trips aboard various makes & models of
outstation highway coaches plying the SGP-KL route over the last 10
years. That's why i wrote earlier that the drivers tend to NOT
observe the green zone simply because if they stay right in the
middle of the green zone it'll only yield a road speed of 60 to 80
km/h, obviously to me too slow for prolonged long distance highway
driving.
I notice on many models if they stay @ the end of the green zone
before the start of the red zone, then they get ~ 100 km/h. But
i'll say due to impatience & the perception (which i somewhat
would agree) that even 100 km/h can be not productively fast enough
sometimes on the N-S highway, they then tend to exceed into the red
zone 'now & then' in order to get to 120 to 130 km/h ! I
suppose watching the temperature gauge needle going up too much is
likely the real reason why they know they better not be in the red
zone too long @ any 1 time ! Not because they think they're going
too fast or almost any other reasons.
So what i've mentioned above are the more realistic operating
conditions many (outstation highway) coaches are subjected to.
Blind eye seems to be shown to whatever theoritical 'ideal' green
zone operating engine speeds etc. Instead the drivers all seem keen
only in extracting every bit of performance out from the coach in
return for completing their journeys as quickly efficiently safely
as possible, having to juggle constantly with these factors as they
drive & trying to produce the best combination outcome. How
they treat the vehicle seems secondary to them ! That seems the
widespread mentality, understandly so.
Surprisingly then it may seem that despite such 'extreme' operating
conditions, i don't tend to see many breakdowns often ! But what
i've seen quite a few times is that some drivers like to open the
bonnet & 'expose' the engine presumably to cool it down while
the passengers go to toilet & makan @ the rest stops along the
highway ! I hardly observe such a practice with citybuses @ the
terminals though.
Of course for coaches which are driven mainly or only within
Singapore, these would have a much better life than those highway
coaches above ! If you compare these (within Singapore use only
hence low overall road & engine speeds driven) coaches with
citybuses, then only would i agree that in such situations ONLY,
the overall wear & tear levels on the citybuses would be
higher.
Next time you take a coach to KL or Penang etc., make sure you get
a good seat, to me that means a single seat either 1st or 2nd row
where you get a vantage view of what's actually going on in the
cockpit then observe the road & engine speeds &
temperatures if possible. See then if my observations are accurate
or not.
