This is very interesting given the arguments now looming over the land-use change effects of the push towards biofuels. The net effect on life cycle emissions of CO (but see below) is purported to be a reduction of between 10 per cent and 100 per cent, depending on what exactly is included in the calculation (eg the source of the biofuel the amount and type of fertilizer used in the crop production and the energy used in the production process), the blend of fuel used and the type of conventional diesel to which the biodiesel is added(EPA, 2002). Emissions savings from biofuels can vary widely. The use of wheat-based ethanol produced CO savings from as little as 7 per cent to as much as 77 per cent in the United Kingdom (Defra, 2007). Turning to energy efficiency, the EU estimates that fuel consumption increases by about 10 per cent with the use of biofuels. The IEA argues that because of the higher cetane number of biodiesel, it has a higher burning efficiency and this, combined with the fact that the lubricity of biodiesel is higher, means that the energy efficiency is just a little below that of traditional diesel.