PowerTorque - by Dave Whyte
Still a rarity in Australia, CNG could be the way of the
future as David Whyte finds out from Isuzu
Inner city pick-up and delivery work is not for the faint
hearted, with stop-start traffic and tight access to delivery docks
making life hard for those involved. The increase in courier style
deliveries over the last few years has resulted in increasing
numbers of small to medium trucks on the roads in our major
Although these trucks don't cover huge distances each day, they
do have a hard working life, with only short distances between
deliveries. This type of operation has a huge impact on the
environment due to frequent starting and acceleration, and the
associated fuel use. The good news is that someone has come up with
a way to run these vehicles cleanly, and just as importantly,
The talk of alternative fuels for commercial vehicles has been
going on for years. Ideas of new fuel types, increasing diesel
engine efficiency, and even hybrid vehicles have been circulating
with very little proof of their effectiveness thus far. In response
to this, Isuzu has recently released its range of Compressed
Natural Gas (CNG) vehicles to the Australian market.
Isuzu is not new to CNG technology, having 20 years experience
using this fuel in Japan (albeit a country that imports its CNG).
Since the early 90's, Isuzu has sold over 10,000 CNG powered trucks
and is proud to claim a 70 percent share of the commercial CNG
market in Japan. Even in Iran, one of the world biggest oil
producing countries, CNG has proven popular as an alternative fuel.
In just five years, thanks to government incentives, CNG vehicles
have gone from virtual non-existence to now occupying seven percent
of the automotive market. This begs the question, why has it taken
so long to get here?
In terms of an alternative fuel, CNG is the perfect choice for
Australia. Being the world's fifth largest producer of natural gas,
and with huge reserves still underground, the issue of future
supply is well assured. Local production also means easier long
term fuel price forecasting, allowing operators to more accurately
determine the ongoing cost of operating CNG powered vehicles. With
the current cost of CNG being around 33 cents per litre, the
ongoing financial benefits would seem obvious. The real benefit for
most of us, though, is environmental.
The engines used to power the Isuzu range are not converted
diesel engines, but are specifically built to run on CNG. Not only
do they exceed the impending Euro 5 emissions regulations, but they
are claimed to meet some of the criteria for Euro 6, for which an
implementation date has not even been set in Australia. It is
claimed that these engines produce 15 to 30 percent less greenhouse
pollutants than their diesel equivalents, including zero
particulate matter (PM). So clean are these engines that it begs
the question as to why Isuzu would continue to build diesel engines
at all? The official line, though, is that diesel is the fuel of
choice for Isuzu into the near future.
Isuzu's CNG range, for the moment at least, consists of three
basic models covering GVMs from 4.5 tonnes through to 14 tonnes.
The lighter end sees the NLR200, with a GVM of 4.5 tonnes, fitted
with the 96kW (129hp) 4HVi engine. At just over 4.5 litres, this
engine is naturally aspirated, with multipoint injection and a
three way catalyst to achieve these low emissions. Mated to a five
speed AMT, with no clutch pedal, this provides plenty of power for
a relatively small truck. Maybe even too much, as the little truck
didn't seem to have the weight to maintain momentum during the gear
change on flat ground. This made for a jerky gear change from first
to second, and second to third. With a bit of speed up, the higher
changes came through more smoothly. Cab fitment and layout are
identical to the diesel equivalent, though the new touch-screen
multimedia unit was a nice touch.
The NPR300, with a GVM of 7 tonnes, uses the same powerplant but
this time matched to a six-speed AMT, again minus the clutch pedal.
The gear changes were remarkably better in this unit, though this
may be due to the different ratios involved. Even with the extra
weight, around 5300 kg for our run, this engine performed very well
in local traffic conditions. Again, the lack of diesel "knocking"
was noticeable, both at idle and under load. Noise levels in the
cab were low, with conversation easy at any speed. This truck was
fitted with optional cameras which beamed pictures through
themultimedia unit, giving a good view down both sides and behind
the truck. A handy touch on a truck this size, given the places
they access are often amidst distractions such as traffic and
The highlight of my day, though, was the FSR850. With a GVM of
14 tonnes, this is the biggest available with a CNG powerplant.
Powered by a 7.8-litre, turbocharged, six-cylinder engine, giving
out 162kW (217 hp) and 735Nm of torque, this engine actually
surpasses the power output of the diesel it replaces. Fitted with
an air-assisted, six-speed manual gearbox, which gave a slightly
clunky, but direct change, this was my pick of the bunch.
Loaded to just over 10.3 tonnes during our drive, I was lucky
enough to get the gig of driving it up Arthurs Seat, a fair climb
with some good, almost hairpin, bends involved. The torque really
kicked in at around 1100 rpm, meaning it was a simple case of
select a gear and use the accelerator to manage speed in the
corners. Engine braking has never been a strong point on any
Japanese truck, and things were no different here. One of the many
plus points for this model is the benefit of the standard ISRI
suspension seat, making the driving experience more comfortable for
the operator over longer distances.
Speaking of distances, the operating range on these units is
best suited to back-to-base operations. With an operating range of
about 300 km for the two smaller trucks, and 400 km for the FSR,
long distance running is all but out of the question. Isuzu is
spruiking the value of companies having on-site fuelling
facilities, making daily refuelling simpler. With most transport
depots being close to a main gas pipeline, this would seem to be a
logical choice for larger fleets. It would also solve the problem
of limited public CNG fuelling sites available at present. This
issue should sort itself out over time as demand becomes greater
and more sites are built to serve and support the growing
In a promising sign for Isuzu, two large fleets have placed
orders for new model CNG trucks. These are in addition to the units
being operated by various councils around the country at present,
and may well be the start of something big. With the current
emphasis on environmental responsibility, and talks of an Emissions
Trading Scheme perhaps not being too far away, Isuzu couldn't have
picked a better time to introduce these models to the Australian
market. With a cheaper fuel source, and guaranteed supply from
local fields, along with ultra low emissions, the future looks good
for CNG powered vehicles, and Isuzu is ready to lead the way.