Classical Gas

PowerTorque - by Dave Whyte

PowerTorque
Issue 35

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 cities.

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, affordably.

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 pedestrians.

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 market.

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.