Contemplating buying the ECODIESEL

Have been reading many of these forums in anticipation to buying. Currently am driving a '98 Ram 1500 4 X 4, 5.7 liter, 145k on the odometer. The most mpg I've gotten since new has been 13.5 mpg. Looking forward to the increased mpg with the ECODIESEL. Must sell the gas burner first. Haven't seen any info or reports of anyone burning Bio Fuel. Dodge literature says B20 is approved. Would Bio attain better mpg due to the increased lubricating ability? Any input would be appreciated!