In my country, the government's "generous, all things considered" cost of operating a private car* is 45p per mile - which covers not just fuel, but also depreciation, insurance and suchlike.

Meanwhile, a 12-minute, 4 mile Uber journey would cost me £2.43/mile

Of course, the big unknown here is one of driver utilisation: How many miles does the driver drive to pick me up, and how many minutes are they waiting for the next ride to come in?

* Well, it was considered generous the last time I asked a car owner about it. I'm sure a Lamborghini costs more.