Business Tax Strategy Tax Case Study

The G-Wagon Tax Write-Off: How Section 179 Turns a $185,000 SUV Into a $157,250 Deduction

Buy a heavy SUV for the business and the IRS lets you deduct most of the purchase price in year one. Here is how the 6,000-pound weight threshold, Section 179, and bonus depreciation combine on a $185,000 Mercedes G63 — and where the audit exposure sits.

Core-AI Research Team · August 25, 2026 · ~2 min read · Case data: IRS Publication 946, IRC §179

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Plug in your own purchase price, business-use percentage, and tax bracket to see your exact first-year write-off before you buy.

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The 6,000-Pound GVWR Rule: Bypassing the Luxury Auto Depreciation Cap

Under standard IRS rules, ordinary passenger cars are subject to strict luxury automobile depreciation caps (limiting year-one write-offs to roughly $20,200). However, vehicles with a Gross Vehicle Weight Rating (GVWR) exceeding 6,000 pounds—such as the Mercedes-AMG G63 (7,055 lbs), Cadillac Escalade (7,600 lbs), Lamborghini Urus (6,327 lbs), and Tesla Cybertruck (9,169 lbs)—are classified as heavy transportation equipment, qualifying for uncapped first-year bonus depreciation.

First-Year Cash Math for S-Corps and LLCs

When an S-Corp or LLC owner purchases a $185,000 G63 with 85% business usage, they create an immediate $157,250 tax deduction. At a top marginal combined federal and state tax rate of 46.3% (e.g. California or New York), this generates $72,836 in direct cash tax savings in Year 1, effectively reducing the net out-of-pocket acquisition cost to $112,164.

Run your own numbers

The exact split between the Section 179 deduction and bonus depreciation shifts with the vehicle price, business-use percentage, and tax bracket. The Section 179 SUV calculator walks through that math for your own purchase.

Compliance Audit Triggers: Mileage Logs and Recapture Risk

To defend against IRS audit scrutiny, business owners must maintain an irrefutable contemporaneous mileage log verifying that business use remains strictly above 50%. Dropping below 50% business use triggers severe depreciation recapture, converting previous tax write-offs back into ordinary income.

Disclaimer: The figures above are an illustrative case study, not individualized tax advice. Section 179 and bonus depreciation outcomes depend on your vehicle's GVWR classification, business-use percentage, and your full tax return. This article is for educational purposes only and does not constitute tax advice. Consult a licensed CPA or tax attorney before making any vehicle purchase decisions.

Written and verified by the Core-AI Engineering Desk — last reviewed September 1, 2026.