My bikes that I have had, are about mid-range in operating costs compared to my other vehicles I have or have had recently,
I use them for business, so I have a good tracking of all costs my most inexpensive vehicles to own and operate, surprisingly, BMW 3 series cars, a 320i @24¢/mi and a 325e at only 23¢/mi, my SV650, came in at 36¢/mi, more than a couple of Jeep Cherokees that were 33¢ & 35¢, My V-Strom, is up there @ 45¢, higher than my Silverado 42¢, my most expensive, vehicle, a full size Chevy G30 van @ 53¢
everyone thinks I ride to save $$, maybe on a smaller bike, my V-stom, $300 worth of tires every 5k, chains, sprockets, more frequent oil service, adds up, and they depreciate in value faster than a car, if you put comparable miles on them, what is a 3 year old SV650 with 100k worth, not as much as the 3 year old BMW 325e with 100K (proportionately)
but I don't own scooters , and my K-Pipe, I haven't had around long enuf to come up with a real figure, but I'm hoping below 20¢, I didn't pay much for it, and it goes a ways on gas, insurance is cheap, but haven't had to replace other consumables yet.