The case against diesel: Part II

Holden was rumoured to be working on a diesel V6 version of the locally-manufactured Commodore a couple of years ago. As rumour had it, the VM Motori 2.9-litre engine developed in Italy and fitted to the European-delivered Cadillac CTS was the engine of choice for the Commodore. But things have gone quiet on that front in recent times.

Somewhere along the line, the local GM subsidiary made the decision to forego diesel power for the Commodore. It's the stuff of conspiracy theories as to why, but as with Ford Australia's Falcon, there are just plain better alternatives available -- alternatives that cost less in R&D investment or fit better the local market's needs for a variety of reasons. Some of those reasons are consumer-oriented, some environmental and some legislative.

Jonathan Rose, Senior Manager of Product Communications at Holden explained in some detail to the Carsales Network why the company chose to go with E85 flex fuel, rather than diesel for the Commodore range.

"We are looking at a range of fuel-saving technologies and alternative fuels to help reduce our dependence on foreign oil," he said, outlining one significant factor Holden has asserted in the past for the adoption of E85-capable engines in the Commodore range. Basically, E85 is a 'biofuel' that is 85 per cent ethanol by volume, blended with petrol. Ethanol, distilled locally, reduces the petrol dependency of flex-fuel-capable cars by a nominal amount of 85 per cent.

"We believe the most effective way to [reduce dependency on foreign oil] is to find multiple ways to improve fuel efficiency and embrace different energy sources," said Rose.

"For us, that means continuing to improve the efficiency of internal combustion engines, both petrol and diesel.  In recent times this approach has seen us introduce Spark Ignition Direct Injection technology to our V6 Commodore range and Active Fuel Management of all automatic V8s -- both significant undertakings."

Holden's continuing commitment to internal combustion engines dovetails with the views of other car companies that as much as 80 per cent of new cars hitting the road in 2020 will still be powered by this type of engine.

"Our strategy also means intensifying our efforts with sustainable, alternative fuels such as E85 which we will bring to market later in the year," Rose continued. "Ethanol is a renewable fuel and the costs are relatively small to modify existing engine technologies to make it viable. We believe it has great potential, particularly the ability to produce it from waste."

The affordability of R&D to develop an E85 Commodore is one good reason in favour of the biofuel. There are a number of other advantages to E85-capable cars also. Firstly, price volatility at the petrol pump will subside somewhat because the ethanol in E85 can be distilled locally and won't be subject to currency exchange rate fluctuations.

Holden claims too that ethanol can be beneficial to the environment, since it can be extracted from plant crops that actually absorb CO2 from the atmosphere and convert it to oxygen. And for those who argue that E85 production will send the cost of crop-based food production skyrocketing, Holden is partnered with an American company, Coskata, to establish local ethanol production on a huge scale -- relying on the re-processing of waste products to produce the chemical.

In short, ethanol is a renewable fuel that's largely carbon-neutral. By comparison, diesel produces soot and CO2 emissions, since the diesel fuel is more carbon-dense than petrol. It's bad for the environment and ultimately a finite resource also.

"LPG is another important option," Rose continued. "We have gone to great lengths to promote the benefits of LPG for the Commodore range, which we think presents an attractive fuel alternative.

"We see diesel as another important alternative fuel that continues to grow in popularity within certain segments. We currently have diesel models of Cruze, Epica, Captiva and Colorado and they each provide attractive fuel economy."

So Holden, like Ford, is not 'against' diesel, it's just that there are economic arguments to counter its viability in the locally-manufactured large cars.

"For our large car range," said Rose, "we need to be mindful that diesel engines aren't cheap. There are not a lot of people who can afford expensive diesel engine technology that doesn't necessarily pay itself back."

Once again, and as with Falcon, unique models built and sold in a small market don't necessarily warrant the expense of a diesel power unit. Furthermore, Holden's decision to go with E85 rather than diesel says something about the company's future export plans. E85 is a fuel that is sold in America, but diesel is increasingly problematic in the US market. Taking the line of least resistance, Holden can export a car that will run on the US market's biofuel for spark-ignition engines. For European markets, the Commodore is possibly too large for more than niche-volume sales -- yet again, it's hard to justify diesel development.

And the same arguments that apply in Ford's case also apply in Holden's. LPG and E85 alternatives in the Commodore range can more than compensate for the lack of a diesel, depending on the driver's needs. Plus both spark-ignition alternatives could be adapted for future mild-hybrid/auto-stop operation with greater ease than a diesel engine. Holden also has this added arrow in its philosophical quiver: E85 is a biofuel that will be viable even with upcoming emissions regulations, biodiesel won't, necessarily.

But Rose leaves the way open for a diesel Commodore, despite the arguments against it sounding virtually insurmountable.

"We never say never. If we see greater demand for diesels in the large car segment, we would always consider that as an option."

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