What is the advantage of a 6-speed transmission?

“Its advantage is that it lets you make easy use of the full power of the engine. MotoGP race machines and supersport models all have 6-speed transmissions. And the YZF-R15 has a 6-speed transmission too. Even if you have a high-performance engine, the power development is going to be different in the different rpm ranges. The reason for a 6-speed transmission is to be able to make the most of the engineʼs power at any point in the rpm range. It eliminates the need to over-rev the engine, and that contributes to better fuel economy.”