The 11% or greater figure has always made me wonder why (when there is a sticker) it almost always says 'may contain a biodiesel blend between 5%-20%'. That certainly doesn't help differentiate between tax-break qualifying diesel or not. Interestingly, I've never seen a sticker that says 11% or greater. Most of the places serving up bio-blends charge as much or more than Meijer's (one of the last sellers of straight D2 around here).What he should know is that for the fuel to have the tax break in Illinois it has to be greater than 10% bio hence the most common blend is B11. Anything greater than that will probably cost more, as bio is usually more expensive than D2. His stickers should read Contains 11% bio or more as I doubt he is receiving anything less than that. Anything up to B20 has been approved by VW for TDI owners in IL
Drive more worry less.