GM and its Australian arm, GM Holden, however, have given technological and financial support to challenge entrants as part of the car maker's interest in potential future fuel needs and energy efficiencies, which mean lower carbon dioxide emissions.
The Panasonic World Solar Challenge begins in Darwin on Sunday on its 3021km-run south across the Outback to Adelaide.
The GM-backed entrants include a petrol-electric hybrid car, sun-powered solar cars and a production car running on fuel that is 85 per cent ethanol; a renewable energy resource.
GM Holden director of innovation engineering Richard Marshall said although the company was committed to alternative propulsion break throughs, diesel fuel now was the best solution for typical Australian driving needs.
“We think drivers will begin to understand and choose the alternative powertrain solution that suits their transport needs,” he said. “Where drivers spend most of their time in heavily-congested traffic, petrol hybrids may offer the appropriate level of performance with low fuel consumption."
“For people whose driving habits typically include a mix of inner city, suburban and country driving, diesel vehicles may be more likely to deliver powerful performance and better fuel economy."
“In Australia, most driving falls into this latter category where relatively low-density residential suburbs, rapidly-spreading coastal fringes and long distances between rural population centres are generally more suitable for diesel power trains.” Mr Marshall's assessment is all the more interesting because no hybrid or diesel car is made in Australia.
GM Holden is experimenting with a diesel Commodore but says at $50 million to develop, plus tooling costs, it is too costly to put into production yet. A hybrid Commodore would be priced too high to attract buyers; unless government incentives and subsidies were given.
GM Holden spokesman John Lindsay said the company offered diesel engines in imported models, the Atra small car, Captiva SUV and Rodeo ute.
The government's green vehicle guide website rates the Astra diesel fuel use at just 5.9 litres/100km, which is 20 per cent more frugal than the petrol Astra's 7.4 litres/100km.
The diesel Captiva is rated at 8.6l/100km, or 25 per cent more economic than the petrol Captiva's 11.5l/100km.