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  • Mitsubishi Fuso Authorized Dealer
    Established 1967
  • 1505 N 4th St. San Jose, CA
  • 408-263-7300
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Opacity Testing for Commercial Vehicles

Diamond Commercial Vehicle Service Bays San Jose

Diesel smoke opacity testing for commercial vehicles is an essential tool in evaluating your exhaust and emissions system’s performance. It is required annually by the state for all heavy-duty commercial trucks, vans, and buses over four years old. Opacity testing offers many commercial vehicle maintenance benefits, ensuring your diesel particulate filter and catalytic reduction systems, which eliminate harmful nitrogen oxide gases from the exhaust, are functioning properly. These issues are among the costliest fleet maintenance expenses which, left unaddressed, could lead to thousands in repairs.

Diamond Mitsubishi Fuso is a Certified Bay Area Opacity Testing Location

Diamond Mitsubishi Fuso offers opacity testing for many sizes and makes of commercial trucks, including:

  • Chevy
  • Dodge
  • Ford
  • Freightliner
  • GMC
  • International
  • Iveco
  • Kenworth
  • Mack
  • Mercedes
  • Peterbilt
  • Sprinter
  • Sterling
  • Volvo
  • Western Star
  • Workhorse
  • And more

Commercial Vehicle Opacity Testing Procedures

We follow best practices for opacity testing, measuring opacity – the amount of light blocked by particulate matter and smoke in diesel exhaust – using the snap-acceleration test and RPM recording at idle and maximum governed speeds. We also inspect for visible signs of tampering with the system as required by law.

It is essential to conduct annual opacity testing to avoid penalties. Each vehicle must have two years of California opacity testing records to avoid citation/fines of up to $500 per vehicle per year. The California Air Resources Board (CARB) enforcement staff conducts random roadside and weigh station testing to ensure compliance.

Opacity Testing Limits

Beginning in 2019, heavy-duty diesel-powered vehicles with a gross vehicle weight over 6,000 pounds must meet the following criteria:

  • Pre-1991: 40% opacity limit
  • 1991-1996: 30% opacity limit
  • 1997-2006: 20% opacity limit
  • 2007 and newer: 5% opacity limit
  • Engines with a level 2 verified diesel emissions control system: 20% opacity limit

Commercial Vehicle Opacity Testing in the Bay Area

Diamond Mitsubishi Fuso offers affordably priced opacity testing in our shop, as well as mobile opacity testing, call for a quote.

We have a large service center and a fully stocked parts warehouse. If your commercial truck fails an opacity test, we can help you achieve compliance, avoid fines, and get your vehicle back on the road fast, repairing and retesting your vehicle.

Ensure compliance and avoid fines with opacity testing for commercial vehicles from Diamond Mitsubishi Fuso. Contact us at 408-263-7300 to make an appointment or schedule mobile opacity testing services at your San Jose, Santa Clara, Milpitas, Morgan Hill, Gilroy, Sunnyvale, or Mountain View location today.

Mitsubishi Fuso Authorized Dealer

Hours of Operation:

Mon – Fri: 8:00AM – 5:00PM

Weekends or After Hours by Appointment

Get Directions!

Diamond Mitsubishi Fuso

1505 N 4th St. San Jose, CA 95112

(408) 263-7300


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