Since 1900, when oil was first used commercially, oil consumption has increased exponentially at about 7% per annum until the 1973 oil crises broke the trend. Oil consumption is still rising, however. The Earth's estimated entire oil depository (used, discovered and non-discovered), of 200,000 million barrels will necessarily run out at current rates of extraction (2,100 million barrels per year), towards the end of the next century. Since the global industrial economy is foremost based around oil-based commercial energy, reducing oil consumption (by improving energy efficiency) will buy potentially invaluable time to allow for a necessary and smooth transition of the industrial economy to other (sustainable) energy sources. The fact that alternative energy sources cannot efficiently produce the fluid fuels on which all industrial economies now depend, and the development of the South modelled on the North will not be able to rely upon and be provided by remaining oil resources, strongly adds further incentives to reduce oil consumption and switch to other energy resources. Besides economic considerations, activities involving oil are contributing to unsustainable environmental degradation, and above all global warming.
An EU directive prepared in 1998 will require national authorities to ensure that buyers of motor vehicles have access to four sources of information on fuel consumption: (1) car-dealers and garages selling new cars would display on each car its fuel consumption and CO2 emissions; (2) posters would provide this same information for all cars on sale at the showroom; (3) manufacturers and dealers would include information on fuel consumption in their advertising; and (4) a guide to car fuel consumption would be prepared and distributed free to the public.