listed vehicle depreciation. maximum first year depreciation based on 100% business mileage is $11,200
based on the fact you can't use 179 or bonus depreciation since business use below 50%
it would seem you answered NO to the question of having a record of personal mileage for full year (10a). since you acquired the vehicle in August the question is really do you have a record of personal mileage since acquisition. there is a separate question of about having a record of business mileage and a second question of it being written. Answering no to having a written record of business usage increases your audit risk and if audited the IRS could deny the deduction as small as it is.
I really don't know how the personal mileage question should be answered. if you take the odometer reading at year end and kept a record of business milage. by simple arithmetic personal miles is the difference. it's not asking if the personal mileage is written.
since you answered no to having a record of personal mileage Turbotax states the following as help for that line
Check the appropriate box to indicate whether or not you have records for the full tax year (actually since acquisition) for any personal miles driven. When no records exist for your personal mileage, a special allocation based on number of months of business use is required to determine your business use percentage. TurboTax automatically computes the number of months of business use and the special allocation when you check "No" here. See the instructions above for what to enter on lines 4a, 4b, 4c, 5, 6 and 7 in this case.
The last sentence seems to be nonsense because it hasn't been updated
I did find this which seem to be to the point
If you checked "No" on line 10a, then lines 5a, 5b, 5c, 6, 7 and 8 should only include those miles actually driven during the period of business use.
thus the 27c is now 5/12 times 495/5103 = 4.04% business usage
27d working backwards the cost is about 115200
27e tax basis is then 115200 times business usage or 4655
27h is then luxury auto limit of $11200 times 4.04% or 453
if 10a was not checked "NO" then depreciation would be 11200 * business usage of 9.7% or 1086
