FJR4JPJ - The manual says to change the final drive oil again at 8000 & 16000 miles. The capacity is 200ml to the top of the fill hole, so a bottle is good for 2.5 changes. After the 16000 mile rear end change (presuming you don't change it more than the recommended 8000 mile intervals, save your money and get some Mobil 1 75-90 synthetic gear oil. It's much cheaper, I change the rear end oil every 4000 miles with the engine oil & filter. Many, many FJR riders use the Mobil 1, Amsoil, Valvoline synthetic instead of the Yamaha juice. When you get around the 8000 mile mark, you'll probably be ready for a rear tire change anyway, so time it with a gear oil change and a shaft spline lube using the Honda Moly 60.