[jondumbau]

Many motorcycles didn't come with cats in the 2000s, combined with lots of high strung 600s running massive valve overlap.

But the modern class of commuter bike has got to be pretty good. Drag coefficient is poor but they're also a much smaller area, and city driving is more forgiving for aero.

[names_are_hard]

This is a key point. Fuel consumption on my bike goes from about 22km/l all the way up to 15km/l if I increase my speed from 70km/h to 130km/h. Essentially the killer is wind drag. I'm riding a bike with notably poor aerodynamics, I suppose sport bikes do better in this regard.