FUEL CONSUMPTION AND EMISSIONS

The combustion of fossil fuels by motor vehicles is a significant contributor to Australia's greenhouse gas emissions. Australia's most recent national greenhouse gas inventory provided data for the years 1990 to 2008. During this period the transport sector's total greenhouse gas emissions increased by 29%. In 2008 the transport sector accounted for 15% of total greenhouse gases emitted excluding land use, land-use change and forestry (80.2 million tonnes) (DCCEE 2010). Road transport was the main source of transport emissions in 2008, accounting for 86% of all transport emissions, or 12.6% of national emissions (DCCEE 2009).

For every litre of petrol used, 2.3kg of carbon dioxide is released. For diesel, this figures rises to 2.7kg but is significantly lower for LPG (1.6kg) (DEWHA 2008). From 1998 to 2007, fuel consumption by passenger vehicles increased from 15.0 billion litres to 18.1 billion litres. In 2007, 88% of the fuel consumed was petrol, 5% was diesel and 7% was LPG, reflecting a relatively similar pattern over the 10 year period (ABS 2007).

While new vehicles are considerably more fuel efficient than older vehicles, the average fuel consumption by passenger vehicles remained at around 11.5 litres per 100 kilometres between 1998 and 2007. This is in part due to the relatively slow drop in the average age of passenger vehicles which has inhibited efficiency gains. In 1999, the average age of passenger vehicles was 10.3 years, while in 2009 this figure was 9.7 years (ABS 2009).