Would anyone have any thoughts as to why the fuel mileage is going down on my 09 Fatbob? The first year I had it I got about 50 mpg, last year I got about 45 and now this year about 41. I have about 13000 miles on it and oil level is ok. I have had all the 5000 mile maintenance intervals performed at dealer and also change oil every 2500 miles. Someone told me it is my riding style but I don't think that would make that much of a difference.