2013 200. Had 33" KO2's on and routinely got about 18mpg. Made the jump to some 34.5 KO3's and fuel economy dropped to around 11. Went back to a set of Toyo Open Country RT in 265/70/18 (33.6") and mileage has not come back. Engine appears to be running as well as ever. just serviced all fluids. Could I have a fuel filter or something that just happened to go down at the same time as the tire swap?