The downsizing of engines in passenger cars may be acceptable
considering naturally aspirated engines are currently the norm and
the maximum weight likely to require shifting is unlikely to exceed
2,000kg, but when you're dealing with commercial vehicles where
turbocharged diesel engines are already the norm, you're dealing
with a completely different kettle of fish.
There are times where additional tax expenditure is unlikely to
dictate decisions made by an operator. The extra money spent
on road tax brings the benefit of higher levels of passenger
comfort (i.e. lower complaints due to rough gearchanges or high
noise / vibration levels) and decreased downtime and operating
costs due to longer life of components that are put under lower
levels of stress.
Going back to fuel consumption, just to give you an idea, a
Mercedes-Benz OC 500 LE with a ZF 6 AP 1400 B TopoDyn gearbox and a
12-litre OM 457 hLA engine with 299 PS returns similar fuel
consumption figures to a Volvo B7RLE with a Voith D864.5 SensoTop
gearbox and a 7.1-litre D7E engine with 290 PS. The OC 500 LE
is clearly more powerful at low engine speeds and has kickdown
function whereas the B7RLE is the weaker performer especially below
1100rpm and does not have kickdown function.
I believe it will come to a time that commercial vehicles will
downsize their engines soon. The car engine technologies are the
test bed for any technological advnaces in the past as they are
smaller and easier to implement and test out before using these
technologies for bigger machines. Once auto manufacturers are able
to produce efficient and lasting smaller engines which can produce
adequate performance and cleaner engines, they will intorduce it to
bigger vehicles. As our fuel sources are rapidly depleting and
booming world population, plus awareness of greener enviroment
globally, this technological advancement has to be improved.
Bus manufacturers have also been trying to downsizing engines,
offering smaller engines with adequate performance. Technologies
might be premature but these will be improved as time passes.
In Singapore context, we are moving more into greener awareness.
The implementation of EURO IV requirements in a few years time will
certainly affect our bus operators' decisions, which they are even
looking into EURO IV and beyond. However as engines move beyong
EURO IV, bus operators are making smaller efficient engines for
stricter emission standards too. How many options they have???
Lastly, our government may also implement carbon tax soon, which
bus operators should also consider this as well. Road tax is
another issue to consider. Right now, our bus operators are
beginning to use smaller engines which are comfortable as well.
