Biofuel B20 (diesel) being tested in SF Bay Area... I have a diesel X5, anyone have any opinions in opposition to Biofuels?? http://www.huffingtonpost.com/2012/11/14/biodiesel-b20_n_2133044.html?utm_hp_ref=san-francisco Ethanol is corrosive, costly, & inefficient. Al Gore backed off on it becau...