For contractors and construction businesses, heavy vehicles and equipment represent the largest capital expenses — and the largest potential tax write-offs. The heavy vehicle tax deduction rules under Section 179 and bonus depreciation let you deduct the full purchase price of qualifying assets in the year you buy them, turning a $350,000 excavator into a $350,000 deduction.
This guide covers the specific rules for heavy vehicles, the 6,000 lb GVWR threshold, equipment depreciation strategies, and real-world examples with dollar amounts so you can plan your purchases for maximum tax benefit.
Section 179 for Heavy Equipment: The Basics
The Section 179 deduction lets you expense the full cost of qualifying business equipment in the year you place it in service, rather than depreciating it over 5-7 years. For 2026, the limits are:
There is no per-asset dollar cap under Section 179 — only the total annual limit. A single excavator costing $400,000 can be fully deducted, as long as your total Section 179 deductions for the year don't exceed $1.25 million. And if you exceed that cap, bonus depreciation picks up the rest at 100%.
Both new and used equipment qualify. Financing through a loan or lease also qualifies — meaning you can deduct the full purchase price even while making payments over five years.
The 6,000 lb GVWR Vehicle Threshold
The IRS draws a clear line at 6,000 lbs gross vehicle weight rating (GVWR) for business vehicles. This threshold determines your deduction limits:
| Vehicle Category | GVWR | Section 179 Limit | Examples |
|---|---|---|---|
| Light Vehicles | Under 6,000 lbs | $20,500 first-year cap | Sedans, small SUVs, half-ton pickups |
| Heavy SUVs | 6,000–14,000 lbs | $30,500 SUV cap | Suburban, Escalade, GLS, X7 |
| Heavy Trucks & Vans | Over 6,000 lbs (non-passenger) | No dollar cap | F-250+, Ram 2500+, cargo vans, box trucks |
| Construction Equipment | N/A (not titled as vehicles) | No dollar cap | Excavators, skid steers, cranes, dozers |
For contractors, the most valuable category is heavy trucks and non-passenger vehicles over 6,000 lbs. These have no Section 179 dollar cap per vehicle — a $75,000 F-350 gets the same full write-off treatment as a $400,000 dump truck. The key is that the vehicle must have a truck bed, cargo area, or be designed for non-passenger use. Heavy SUVs used for passenger transport are capped at $30,500 under Section 179.
Pro tip: Check the manufacturer's door sticker or spec sheet for the GVWR — not the curb weight. A Ford F-150 starts at 6,010 lbs GVWR for certain configurations, pushing it above the threshold. But a base-model F-150 may fall below 6,000 lbs. Always verify before purchasing.
Equipment Write-Off Examples
Here's what full first-year expensing looks like for common construction equipment, assuming 100% business use and the Section 179 or bonus depreciation election:
| Equipment | Typical Cost | Year 1 Deduction | Tax Savings (37% Rate) |
|---|---|---|---|
| Excavator (mid-size) | $250,000–$400,000 | Full cost | $92,500–$148,000 |
| Dump Truck | $120,000–$180,000 | Full cost | $44,400–$66,600 |
| Skid Steer | $35,000–$75,000 | Full cost | $12,950–$27,750 |
| Crane (mobile) | $300,000–$800,000 | Full cost | $111,000–$296,000 |
| Work Truck (F-250/350) | $55,000–$80,000 | Full cost | $20,350–$29,600 |
| Concrete Mixer Truck | $150,000–$250,000 | Full cost | $55,500–$92,500 |
At the top federal bracket of 37%, every $100,000 in equipment deductions saves you $37,000 in federal income tax. Add state taxes and the effective savings rate can reach 40–45% in high-tax states.
Timing: Year-End Purchase Strategy
One of the most powerful aspects of Section 179 is the timing rule: equipment only needs to be placed in service by December 31 to qualify for that tax year's deduction. "Placed in service" means delivered and ready for use — it doesn't need to be actively in use on a job site on December 31.
This creates a strategic window for year-end planning:
- October–November: Review your projected income and tax liability. If you're going to owe significantly, identify equipment purchases you planned for Q1 of next year and pull them forward.
- December: Take delivery before December 31. Even equipment financed with a loan qualifies — you deduct the full purchase price, not just the down payment.
- Documentation: Keep the delivery receipt, purchase agreement, and proof of payment. The IRS may ask when the asset was placed in service.
Planning a major equipment purchase? We'll model the tax impact before you buy — so you know exactly how the write-off affects your bottom line.
Get a Free Equipment Tax Analysis →Bonus Depreciation vs. Section 179: When to Use Which
Both Section 179 and bonus depreciation achieve the same result — a full first-year deduction — but they have different rules:
- Section 179 is capped at $1.25M total and limited to your business's taxable income (you can't create a loss with Section 179). You elect it per asset.
- Bonus depreciation has no dollar cap and can create a net operating loss (NOL) that carries forward to future years. It applies automatically unless you elect out.
For most contractors, the strategy is: use Section 179 first (up to the income limit), then let bonus depreciation handle any remaining equipment costs. If you have a particularly large purchase year — say $2M in new equipment — bonus depreciation ensures you still get the full deduction even above the Section 179 cap.
Bottom line: Heavy vehicles and construction equipment get some of the most favorable tax treatment in the code. A contractor buying $500,000 in equipment can generate $185,000+ in federal tax savings in a single year. The key is verifying GVWR for vehicles, ensuring 100% business use, taking delivery before December 31, and choosing the right combination of Section 179 and bonus depreciation for your income level.