In many parts of the US now, regular pump diesel fuel contains 2% biodiesel, or in some areas it's 5% or 11%. On the state and federal level a minimum component of "renewable" fuel is increasingly being mandated.
In other words, check the label on the pump next time you fill your tank -- if it has a notice that you may be buying B2 or greater, then you don't have to do anything at all.
