If we look at MotoGP, V4s dominate, with Ducati, Honda and Suzuki fielding such machines. Now that Kawasaki has dropped out of the series, only Yamaha is left to fly the inline-four flag. In SBK, the opposite situation holds, with 1000cc inline-fours from BMW, Honda, Kawasaki, Suzuki and Yamaha making up the majority. Aprilia is the lone V4. (I haven't forgotten the 1200cc V-twins of Ducati and, someday, KTM, but we'll stick to the 1000cc fours here).