For business owners, the tax code is rarely described as “generous,” but Section 179 is the notable exception. In 2026, the intersection of updated inflation-adjusted limits and the recent restoration of 100% Bonus Depreciation under the One Big Beautiful Bill Act (OBBBA) has created a goldmine for those looking to upgrade their business fleet.

If you are considering purchasing a heavy SUV, truck, or van for your business this year, understanding the “6,000-pound rule” could result in writing off the entire purchase price in a single tax year.

1. The Magic Number: The 6,000-Pound GVWR Rule

The IRS distinguishes between “light” passenger vehicles and “heavy” business vehicles based on their Gross Vehicle Weight Rating (GVWR). To unlock the most aggressive tax deductions, a vehicle must have a GVWR of more than 6,000 pounds.

GVWR vs. Curb Weight

It is a common mistake to look at a vehicle’s “curb …