As a general rule, drivers should devote 20% of their earnings to insurance, maintenance, gas, and repairs. When this is accounted for, the average Uber driver earnings are barely above the poverty line.
The best way to think about Uber is a reverse loan on your car. If you need money in a pinch that's a way you get it but it's not a way to actually make any sort of decent living.
That's only if maintenance costs are the same (I'm assuming they won't be). I assume there will be much higher vandalism costs and some other costs that are new to owning a car.