G13 coolant additive provides the same exceptional cooling and antifreeze performance as G12++, but is manufactured in an environmentally sustainable way, using glycerin instead of glycol. Glycerin, a bi-product of biodiesel production, is much less harmful to the environment than glycol-based products, which are produced from mineral oil. In comparison with the manufacture of traditional coolant additive, it is estimated that G13 production will produce 11 per cent lower CO2 emissions. So G13 is the coolant you want.