Business Auto: Mileage vs. Actual, § 280F, and the SUV Loophole

Vehicle deductions under § 162 follow either the standard mileage rate framework of Rev. Proc. 2010-51 (and successor annual revenue procedures) or actual expenses under § 168 / § 179. The § 280F luxury auto limits cap depreciation on passenger automobiles, with a critical carve-out for vehicles over 6,000 lbs GVWR.

Standard mileage rate

Under Rev. Proc. 2019-46 (and current updates), the standard mileage rate is available if elected in the first year the vehicle is available for business use and used consistently for that vehicle. Election forecloses § 168 depreciation, § 179 expensing, and bonus depreciation in subsequent years for that vehicle.

Substantiation under § 274(d): contemporaneous log of date, miles, business purpose, and odometer readings. Reconstructed logs are vulnerable at audit. The 2025 rate is 70¢ per business mile (verify current).

Switching from standard mileage to actual is permitted only if straight-line depreciation is used going forward; switching from actual to standard is generally not permitted.

Actual expense method

Aggregate actual operating costs (fuel, maintenance, insurance, registration), depreciation under § 168 or lease payments under § 162, allocated by business-use percentage (business miles divided by total miles).

Depreciation method default: 200% DB over a 5-year recovery period for autos under § 168; mid-quarter convention triggered by 4th-quarter heavy buying.

§ 280F luxury caps

For passenger automobiles placed in service in 2024 with bonus depreciation: year 1 $20,400, year 2 $19,800, year 3 $11,900, year 4+ $7,160. Without bonus: year 1 $12,400. Annual indexing under § 280F(d)(7). The 2025 numbers will be slightly higher.

The caps apply to passenger automobiles as defined in § 280F(d)(5): any 4-wheeled vehicle manufactured primarily for use on public streets, roads, and highways and rated at 6,000 lbs or less unloaded gross vehicle weight.

Trucks and vans use GVWR (gross vehicle weight rating, including payload) for the 6,000-lb test. SUVs are vehicles built on a truck chassis and use GVWR. The classification is on the manufacturer’s door-jamb plate.

The 6,000-lb carve-out

Vehicles above the GVWR threshold are not subject to § 280F(a) caps. Full bonus depreciation under § 168(k) applies (current phase-down: 80% 2023, 60% 2024, 40% 2025, 20% 2026). § 179 expensing applies, capped at $30,500 for SUVs (2024) under § 179(b)(5); non-SUV trucks and vans (e.g., cargo van, pickup with cargo bed ≥ 6 feet) are subject to the general § 179 dollar limit ($1,160,000 for 2024) without the SUV cap.

Business-use threshold under § 280F(b)(1): more than 50% business use is required for accelerated depreciation. Falling below 50% in a later year triggers recapture under § 280F(b)(2) equal to excess of accelerated depreciation over straight-line.

Lease inclusion amounts

For leased vehicles above the § 280F threshold values (around $62,000 in 2024 for passenger autos), lease inclusion amounts under § 280F(c) and Reg. § 1.280F-7 add a small amount back to income annually to neutralize the lease vs depreciation arbitrage. The amounts are modest (typically several hundred dollars).

Heavy vehicles above 6,000 lbs GVWR are not subject to lease inclusion.

Personal use and fringe benefits

For a corporation-owned vehicle, personal use is a taxable fringe benefit. Valuation methods under Reg. § 1.61-21: annual lease value, cents-per-mile method, or commuting valuation. Commuting valuation ($1.50 each way) requires written employer policy prohibiting non-business use.

For >2% S corp shareholders, the personal-use value is wages reported on W-2.

Practitioner posture

1. Default to standard mileage for newly-acquired vehicles unless modeling shows actual will exceed. Reverses are limited.
2. Heavy SUV planning requires confirmation of door-jamb GVWR > 6,000 lbs; common vehicles in this range: full-size SUVs (Tahoe, Suburban, Expedition, Land Cruiser), large crossovers, most pickup trucks.
3. 50% business-use floor must be maintained or expansive recapture triggers; document business miles contemporaneously.
4. Accountable plan + personal vehicle often cleaner than corporate ownership for S corp clients; avoids personal-use fringe benefit complexity and § 280F caps don’t bind the employee on a vehicle they own.