If you work for a company, drove clients that were in town around and were not reimbursed, then yes you can claim the gas you used to transport them.
To claim gas expenses:
1. Select "Federal Taxes" at the top of the page
2. Select the "Deductions & Credits" sub-tab
3. Scroll down to "Employment Expenses" and select
"Show More"
4. Select "Start" next to "Job Expenses for
W-2 Income"
5. Select "Edit" next to your occupation(Or enter it
when asked)
6. Continue forward through the screens answering the questions to enter
your vehicle information and to enter mileage
7. After entering your mileage you should arrive to a screen asking
"Do You Want to Enter Your Actual Expenses?", answer "Yes".
Here you can enter your gas expenses, repair/maintenance expenses, etc.
8. Continue entering your information until finished
Job-related Expenses
