Yes, if you are claiming a deduction for auto expenses for mileage that you incurred for your business.
The problem is that the IRS requires you to keep adequate records or provide sufficient evidence to support your own statement.
If you indicate that you have no records, or that you don't know what your mileage is, you will not be able to claim a deduction.
Please see this IRS link:
And here is an interesting article about this topic:
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