When I add my vehicle mileage and expenses my refund goes to 0, if I don't add my mileage I get a refund?

It could be possible that your actual expenses are higher than your standard mileage rate deduction.  

 

When entering your mileage, you should see a screen which tells you which option provides the higher deduction. 

 

It then gives you the option to select the method. 

 

 

 

Review your input in the auto section to confirm you have entered everything and chosen the method which will yield the best result for you.

 

 

Assuming you are entering mileage for a Self-Employed business, you will go to the Federal Section of the program.

1. Go to the Income & Expenses section
2. Select Self-employment income and expenses
3. Select Review next to the business
4. Select Vehicle - Review
5. Click edit on the vehicle you need to correct your mileage for
6. Continue through the screens until you see the section asking about tracking miles
7. Enter your updated mileage

TurboTax will recommend using the method which yields the highest deduction. 

Thanks for the response, I got the issue resolved.