Running B20 you should not expect much difference in performance or economy. B20 is sold at about 100-150 stations across the country, the reason it is sold as B20 is because it has very little effect on your engine or fuel system. Should you decide to start running B100 you will see a noted increase in fuel economy and a gradual increase in performance as the carbon is cleaned from the inside of your engine. It is the higher biofuel ratios that require fuel filter changes before and during the first 1500-3000 miles. BTW, you may not be aware but gas engines can benifit greatly from biodiesel. They are capable of running up to a 15% mixture.