And this is why working under this scenario, the vehicle is a money losing asset (where every dollar you earned driving costs a dollar in vehicle depreciation, even with a tax deduction, it's still a money losing asset).

The deliverer has to be able to earn $1.15 (at least) per dollar depreciated from the vehicle for the work to be "worth it".

The other issue is uncertainty - you have no idea how much you will earn on a given day or if this will be the day your car finally hits one pothole too many and dies.

But you can estimate it. Record your earnings every day, any compare it by the hour, day, week, and month, as well as miles driven each day. Estimate the total cost of driving (IRS estimate of ~$0.50/mile is a good place to start). Use this simple formula:

(Income - expenses) / hours worked = hourly wage

Is your hourly wage reasonable? If so, it may make sense to optimize away your expenses and generally stay the course. If it's not, would changing your work hours or location make it reasonable?

Unfortunately, I get your feeling that people only look at the income and ignore the rest of the equation (hey, I got $50 tonight! I had to drive 100 miles though...). If you're making $3/trip, you had better drive less than 6 miles or you just lose.