From Yamaha: Light, powerful and bristling with knowledge gained from years of racing, the YZF-R6 is the most advanced production 600cc motorcycle Yamaha - or anybody else - has ever built. The YZF-R6 was the first production motorcycle with a fly-by-wire throttle system for flawless response under all conditions. YCC-I, Yamaha Chip Controlled Intake, is used on the R6 to vary intake tract length for excellent cylinder filling and a broader powerband. On the higher revving R6, its benefits are even more pronounced. Slipper-type back torque-limiting clutch greatly facilitates braking/downshifting from high speed. The YZF-R6 achieves fuel economy up to an estimated 40 mpg** with a fuel tank that holds 4.6 gallons of gas.