Hybrid or alternative fuels?

There was a time when diesels were for trucks or serious off-roaders. With the immediate sales success of Holden's Captiva Diesel, even the not so hard-core diesel SUVs are beginning to find a market in Australia.

Have we finally overcome our morbid fear of compression ignition technology?

Well, judging by the inroads small cars with turbodiesel engines have made, fuel saving is very much on the agenda for Australian new car buyers -- and if that means diesels, they'll do.

The situation appears different in America, where petrol prices have long been lower than in other developed markets. The resistance to diesels seems to be greater in the home of the free -- or at least the home of the very cheap.

That's why American GM brand Saturn is planning to market two hybrid-drive models of the company's Vue, Saturn's version of the Captiva, but no diesel version!

Respected industry publication, Automotive News, reported that the Vue will go on sale with hybrid drive technology next year. Tellingly, the hybrid Vue with automatic transmission is claimed by a GM Powertrain spokesman in the article to improve fuel economy by up to 45 per cent, when compared with the non-hybrid Vue – fitted with the same size engine as the hybrid's.

Saturn is by no means a pioneer in the field. Every volume-selling manufacturer in America has at least one hybrid-drive vehicle in production or due to roll out shortly. In Australia, we have two Lexus models, one Toyota and one Honda.

What's the difference? It's one thing to suggest that Americans look down on diesel technology, but why is the take-up of hybrid-drive technology so conversely slow in Australia?

If you ask an engineer, hybrids are an inelegant solution, but in practice, it's hard to look past the benefits they bring. They can generate torque at speeds where reciprocating internal combustion engines are struggling and a petrol/electric hybrid combination need not be much heavier than a typical diesel engine.

The lack of interest among the local car companies might have something to do with the cost of the hybrid-drive systems. In the case of the Captiva, the difference in price between turbodiesel and petrol variants is just $1000 so any nett gain in fuel economy will pay for that difference within a relatively short space of time -- especially now the gap between petrol and diesel prices has narrowed (or in some cases closed completely).

John Lindsay from Holden admits that "hybrids aren't necessarily the way forward" and "GM globally hasn't nailed its colours to one particular technology."

GM is still looking at all the various alternatives to save fuel. There's diesel of course, the ever popular (in Australia) LPG…and hybrid drives too, but there's also E85 engines, fuel cells and hydrogen combustion. GM is currently conducting research on all of them.

E85 is a mix of 85 per cent ethanol. It's already available commercially in the US, as is 'Bio-Diesel'. Saab is about to launch their new 9-3 range with 'flex-fuel' engines that will run on a fuel mix of up to 85 per cent ethanol.

There are more radical solutions such as 'Bio-Butanol', which can be extracted from algae and offers a yield at least 30 times greater than an ethanol yield from a conventional crop.

In future, we may be faced with a whole slew of alternatives and combinations, such as Opel's Astra Diesel hybrid concept.

Which way will GM head? No one particular source of motive power stands out as the new petrol combustion engine for the 21st Century, but one thing's for certain, personal transportation won't be making a return to the days of the horse and buggy.

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