Car-sharing service Zipcar has started offering a new pay-per-mile plan in some US cities, a departure from the per-hour system that the company is known for. A Zipcar spokesperson tells The Verge that it is "testing this new pricing in select cities throughout the US," which suggests that it's still a pilot program and won't necessarily roll out widely.

Technically, the pilot is a combination of pay-per-mile and pay-per-hour: in Chicago, for instance, where the new plan is being offered, a fleet of Honda Fits can be rented for $4.50 per hour plus 50 cents per mile on weekdays, or $5.50 per hour plus 50 cents per mile on weekends. Fits do not appear to be offered in Chicago with the traditional pay-per-hour pricing, but a comparable vehicle, the Nissan Versa hatchback, goes for $10.75/hour on weekdays without any per-mile charge.

Zipcar floats the per-mile Fits as a good choice for those occasions when "you just need to make a short trip." Normally, the company's vehicles include 180 free miles per day before accruing additional fees.

Like many others across the auto industry, Zipcar has been experimenting with new business models as it tries to figure out how people want to interact with cars in a post-ownership world. It recently rolled out one-way trips in LA — a possible response to rival Car2Go — and has since expanded to Denver, Seattle, and Washington, DC.