On an e-mission with gas trucks

Daily Telegraph
Saturday 1/5/2010 Page: 38

IT COULD be a case of second time lucky for Isuzu Australia and compressed natural gas technology. The Japanese importer jumped the gun when it introduced trucks running CNG to Australia in 2004. It sold 16 before putting the pin, but Australia's best-selling truck brand is introducing four CNG trucks using multi-point injection technology. There are four CNG trucks including two N-Series models and two F-Series models that promise similar performance to diesel, dramatically reduced emissions as well as significantly reduced running costs.

The initial purchase prices of the four models will rise with a premium of around 20%. Isuzu is not yet ready to say how long it would take customers to cover the premium but said the fuel savings would be significant and would increase if the price of diesel soars. "There is a price premium associated with the purchase of the vehicle, however, the payback from reduced running costs equates to a favourable return on investment," says Isuzu Trucks Australia director, Phil Taylor.

The price of CNG varies and is often bought in bulk using yearly contracts. Some companies receive CNG for around 40-50c a cubic metre, which can be equated to a litre of diesel. Another advantage is the stability of the price, as CNG is not linked to the price of fossil fuel. There are seven public CNG vehicle refuelling outlets here and Isuzu is realistic that the widespread take up of CNG trucks is a long way away.

It is confident vehicle fleets that have a CNG filling station on site, or are prepared to install one, will be interested in its offerings. Given the limited CNG network, the trucks would be used for city and suburban transport. "Given the refuelling practicalities of CNG trucks, practicality dictates that fleets with back to base operations will be our main target," Taylor says. Some fleets have a CNG filling station on site for forklifts and the setup costs are minimal given that CNG is piped to most locations already.

The CNG models come in under the Euro 5 emission standard to be introduced next year and meet many of the ratings required for the Euro 6 standard, which doesn't have an introduction date in Australia. The CNG engines emit a fraction of the particulate matter compared to diesel as well as less NOx. ''These CNG engines provide greenhouse gas reductions in the order of 15 to 30%, and these are conservative figures," says Isuzu Australia product planning manager, Colin White.

The most prominent parts of CNG are methane (90% ) and ethane (6% ). The Isuzu engines have complex sensors that enable to air/gas mix to be varied to make up for the different blends of CNG. Two different engines are used for the four new Isuzu CNG trucks. The light duty N-Series trucks run a 4.6-litre, naturally aspirated four cylinder, while the medium duty F-Series trucks use a 7.8-litre turbo six. Both are based on diesel power plants that have been developed to run on gas. They are single fuel, not requiring any diesel to start or run, and are one generation ahead of the single mixer CNG system used on the last CNG trucks Isuzu brought here.

The 4.6-litre unit in the NLR 200 and NPR 300 produces 96kW (hp) and 353Nm available at 1400rpm. The NLR 200 is fitted with a five speed automated manual transmission, white the NPR 300 has a six-speed AMT. Both have an idle stop feature, which shuts off the engine once the gear selector is put into neutral and the park brake engaged. It fires up when drive is selected. The CNG is held in two 150 litre tanks that sit behind the front wheels at a pressure of 200 bar and allows for a range of around 300km.

The NLR 200 is rated for a 4.5 tonne gross vehicle mass (GVM) and the NPR 300 for a 7 tonne GVM. The turbocharged, intercooled 7.8 litre unit in the FSR 700 and FSR 850 generates 162kW and 735Nm at 1400rpm. The trucks use the six-speed manual with synchromesh for gears two through to six. They have a total of four tanks, three steel tanks and one carbon fibre wrapped tank, which holds 440 litres and allow for a range of around 400km.

As long as you have a supply of CNG, these Isuzu trucks are convincing. Drivers working on runs that return to base would be happy when the boss hands over the keys to one of these. There is a reduction in capacity due to the extra weight of the CNG system yet they are handy and drive well. Big Wheels drove the two light duty N-Series trucks and tagged along in the medium duty FSR 850. The performance of all three trucks is adequate and the low-down torque of the FSR made evident on a run through a hilly area was impressive. That said the trucks were hauling 780kg to 10,300kg of concrete ballast, down on the maximum loading.

The small NLR 200 is easy to drive, the most car-like in the range, and the large engine pushes it along with little fuss. Its gear-changes are not the fastest and the throttle blips on the upshifts can take a while to get used to. Its bigger brother, the NPR 300 moves along well enough. The steering is not as good, it feels light on centre, with heavy resistance when you turn the steering wheel. It requires constant input and correction.

Isuzu Australia is aware of the issue and is looking to its parent company for a fix. This was not an issue in the larger FSR, which rode particularly well and had excellent engine performance. There is no doubt the CNG Isuzu trucks are good to drive. It is the availability of CNG that will determine whether it remains a niche green solution or a mainstream one.