It is in the Business Use Of Vehicle Section.- Business Expenses You have to answer all the questions about mileage, personal use etc.
You can also find it by typing in the search box: Section 179, self-employed business "Jump to the section"
Note: 179 limited to $25,000 * business use % ( must be greater than 50%)
From IRS Pub 463
For sport utility and certain other vehicles placed in service in 2017, the portion of the vehicle's cost taken into account for the 179 deduction is limited to $25,000 X business use percentage.
There s a limit on the total section 179
deduction, special depreciation allowance,
and depreciation deduction for
cars, trucks, and vans that may reduce or eliminate
any benefit from claiming the section 179
deduction.
More than 50% business use requirement.
You must use the property more than 50% for
business to claim any section 179 deduction. If
you used the property more than 50% for business,
multiply the cost of the property by the
percentage of business use. The result is the
cost of the property that can qualify for the section
179 deduction.
Example. Peter purchased a car in April
2017 for $24,500 and used it 60% for business.
Based on his business usage, the total cost of
Peter's car that qualifies for the section 179 deduction
is $14,700 ($24,500 cost × 60% (0.60)
business use). But see Limit on total section
179, special depreciation allowance, and depreciation
deduction, discussed later.
For sport utility and certain other vehicles
placed in service in 2017, the portion of
the vehicle's cost taken into account in figuring
your section 179 deduction is limited to
$25,000. This rule applies to any four-wheeled
vehicle primarily designed or used to carry passengers
over public streets, roads, or highways,
that isn’t subject to any of the passenger automobile
limits explained under Depreciation Limits,
later, and that is rated at no more than
14,000 pounds gross vehicle weight. See the link below for more information.
Pub 463
