When I lived in Tucson, I filled my 1980 wagon with a full tank of B99, when I took it to get emissions tested, they had me change lanes after the first test - then in the second test they passed me. I asked why the lane change, they said the first test came back with 0.00 opacity and they thought the machine was bad. I never made it a habbit to run biodiesel in my cars, but a friend in Tucson told me about this trick and it worked. The B99 burns really, really clean and has alot less of the particulate that dino diesel contains. Worth a try.