^ noglider, so far, I've divided costs (purchase and maintenance) by the miles for which I've used the vehicle. I like dividing by miles instead of by time because it puts the focus on what's been done with the vehicle, rather than on how long it has been owned. It would be possible to buy an expensive bike, never ride it, and calculate a very low cost for it after enough time. However, someone with a cheaper, newer, and more frequently used bike would be doing far more with it.