New Jersey Truck Emissions & Clean-Truck Rules

How New Jersey handles truck emissions

New Jersey inspects heavy diesel smoke, and the smoke limit follows your truck whatever the plate. Any diesel on a New Jersey road has to stay under 20 percent opacity on a 1997 or newer engine, 30 percent for 1991 to 1996, 40 percent for 1990 and older (N.J.A.C. 7:27-14.4, 14.6). A truck 18,000 lb GVWR or more registered in New Jersey must also pass an annual opacity test at a licensed Diesel Private Inspection Facility within 90 days of registration or renewal, and MVC runs roadside smoke checks with the State Police. A roadside failure is $700 the first time and $1,300 the second, cut to $150 and $500 if paid within 45 days with proof of repairs, and skipping the annual test is a $500 summons. The Advanced Clean Trucks rule (N.J.A.C. 7:27-31) is a sales mandate on manufacturers and costs you nothing. Keep your DPF and DEF intact; federal anti-tampering fines run about $45,000 per engine.

What applies to you

• Program: Clean Truck Check
• State rule: 20 percent opacity is your limit in New Jersey on a heavy-duty diesel of model year 1997 or newer, 30 percent for 1991 to 1996, 40 percent for 1990 and older, measured by snap acceleration (N.J.A.C. 7:27-14.6). That prohibition reaches every diesel-powered vehicle operated on New Jersey roads whatever the plate, and it also bars visible smoke of any color for more than three consecutive seconds and any disabled emission control apparatus (N.J.A.C. 7:27-14.2, 14.4). Any heavy-duty diesel 18,000 lb GVWR or more registered in New Jersey must additionally pass an annual smoke opacity inspection at a licensed Diesel Private Inspection Facility within 90 days of registration or renewal, using the rolling, stall, or snap acceleration test, and MVC runs roadside smoke inspections with the State Police (N.J.S.A. 39:8-64). New Jersey separately adopted Advanced Clean Trucks (N.J.A.C. 7:27-31), a manufacturer sales mandate on vehicles over 8,500 lb GVWR, with compliance flexibility for model years 2025 and 2026 (Administrative Order 2025-15), and a one-time large-fleet reporting window that has closed.
• Penalty: $700 for a first roadside smoke emission violation and $1,300 for a second, reduced to $150 and $500 if paid within 45 days with proof of repairs. Skip the annual diesel inspection and it is a $500 summons if law enforcement stops you. The underlying prohibition covers any diesel-powered vehicle operated on New Jersey roads regardless of plate, and carries civil administrative penalties (N.J.A.C. 7:27-14.4, 14.10). ACT non-compliance penalties fall on manufacturers. Federal EPA anti-tampering penalties apply: about $45,000 per tampered engine and about $4,500 per defeat device sold or installed.
• DPF / DEF: Federal EPA equipment nationwide, never delete or tamper with it

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