The tax "relief" you state is because it's an actual expense. It costs, on average, $0.58 per mile to operate a vehicle. If you're earning the equivalent of a f

The tax "relief" you state is because it's an actual expense. It costs, on average, $0.58 per mile to operate a vehicle. If you're earning the equivalent of a full time wage at Uber, you're driving 30-50k miles per year and incurring that expense on those miles. It's not some magic money that you just get to use as the basis of a deduction.