So, i assume Uber drivers are self employed.
Yes.
So end of the year when you do tax filing, what expense you can show beside gas and car maintenance.
You don't file taxes in the end of the year, you do it next year, when the new forms are available.
There are following expenses for Uber drivers:
1) Gas
2) Maintenance and repairs
3) Vehicle depreciation
4) Vehicle insurance
5) Lease or car loan interest
6) Business related vehicle related purchases (such as all weather mats; chemicals like car shampoo, detailers, cleaners, etc, etc, etc).
7) Business related communication expenses (internet, phone, etc).
8) Other business related expenses (such as food and drink, parking, etc).
9) Any other business related expenses.
Here's a thread for you to consider:
http://www.uberpeople.net/threads/canada-revenue-agency-tax-return-2014.14907/