Isuzu Motors South Africa (IMSAF) has started evaluating two types of trucks that use alternative propulsion technologies, with a view to determine their suitability for the African market.

Isuzu is currently testing a compressed natural gas (CNG) fuel truck, and a dual-fuel-powered truck converted to run on natural gas and diesel.

“We’ve built a handful of prototype trucks which are currently being tested in real-world conditions on South African roads by a number of Isuzu fleet customers,” says IMSAF technical services executive Dominic Rimmer.

“If the testing is successful we could see more of these trucks paving the way for a greener motoring landscape in future.”

Testing will continue for at least another 12 months, he adds.

“Our mission is to provide transport solutions to our customers.

“Low-emission vehicles using alternate energy sources would be a great addition to our product portfolio.

“These trucks are not only a vital step toward reducing the emission of harmful pollutants, they will also contribute to the more effective utilisation of limited natural resources for transportation.”

Rimmer says IMSAF has had a number of enquiries from customers hoping to evaluate the trucks.

Possible applications are, however, restricted by the limited CNG refilling network in South Africa.

“We expect demand to grow as the gas refilling network is being expanded,” says Rimmer.

As for the cost, he notes that exact prices are not yet available. However, the baseline expectation is that the dual-fuel truck will deliver a roughly 10% saving in fuel consumption compared with diesel trucks.

With the CNG truck, the litre-equivalent price of CNG is around 40% lower than diesel. Depending on the truck’s average monthly mileage, the return-on-investment ranges between 8 and 24 months.

CNG
IMSAF believes the N-Series range of trucks has demonstrated its capability of meeting the demands and needs of a variety of operators with diverse operational requirements, hence the development of the Isuzu N-Series (NPR300) CNG truck, which also has a stop–start fuel saving system.

CNG-powered engines emit very low levels of nitrogen oxides, carbon monoxide, and hydrocarbon, with virtually no particulate matter emitted at all, explains Rimmer.

Another characteristic of natural gas, of which the main constituent gas is methane, is that it produces very little carbon dioxide (CO²).

The advantages of CNG include a 25% drop in CO² emitted compared with an internal combustion engine, as well as a significant reduction in particulates.

CNG is also regarded as a safe gas, with any leaks dissipating back to nature.

Engine power and torque also remain about the same as traditional diesel engines.

Dual Fuel
Based on the Isuzu FTR 850 AMT model, the locally developed 850 diesel dual-fuel model has a D-gid control unit that determines the optimum mixture of diesel and air/gas required under different loads, dynamically modifying it in real time according to the feedback provided by the engine.

Rimmer says the benefits of the system are similar to the CNG model and include the use of a standard diesel engine; the ability to easily switch between diesel/gas mixture and 100% diesel; minimum effect on torque and power; a reduced carbon footprint; improved engine oil quality; reduced engine noise owing to natural gas’ smoother combustion, and a significant reduction of operating costs.