Commentary: ‘AG’ trucks may still be registered under truck rule

Issue Date: October 29, 2014
By Cynthia Cory
Owners of agricultural vehicles not previously registered with the state Air Resources Board have been given until next Jan. 31 to comply.
Photo/Steve Adler
Cynthia Cory

I have warned before that this is the last time you can register an "AG" truck with the California Air Resources Board, in order to be in compliance with the state truck and bus rule. But CARB has opened its door again, for what I believe really is the last time. If you never previously registered your diesel truck with CARB, you can now do so until Jan. 31, 2015.

In a nutshell—and it's hard to put a 70-page rule in a nutshell—the diesel truck and bus rule applies to any on-road diesel vehicle heavier than 14,000 pounds gross vehicle weight rating that is used on- or off-road in California.

There are numerous ways to comply, a primary option being the AG vehicle mileage extension, which requires diesel vehicles owned by agricultural operators as of Jan. 1, 2009, to have stayed under annual mileage limits listed below, to remain eligible for the compliance extension. Some trucks were previously approved for specialty agricultural vehicle exemptions with no mileage limitations, but those are no longer available except for cattle livestock trucks that are registered by Jan. 31, 2015. An important change is the previous 10,000-mile annual limit has been pushed back until 2020, thus allowing AG vehicles more annual mileage until then.

Engine Year Annual Mileage Limits
  2011 to 2016 2017 to 2019 2020 to 2022
2006 or newer 25,000 miles 15,000 miles 10,000 miles
1996 to 2005 20,000 miles 15,000 miles 10,000 miles
1995 and older 15,000 miles 15,000 miles 10,000 miles

Diesel truck owners can register with CARB online or by downloading a form and submitting information by mail. Use the California Farm Bureau Federation website at for truck rule details, links to the CARB online reporting tool and the mail-in forms. From the home page, find the Issues and Regulations link on the top bar. There, we have listed truck rule information under both the Air Quality and Transportation subheadings. You can also go straight to the CARB website at

Once registered, vehicle owners must report their Jan. 1 odometer reading to CARB by Jan. 31 each year, to show compliance for the previous year. AG-designated vehicles must also be labeled with the letters "AG" on the left and right doors, in white block lettering 3 inches high on a 5 inch-by-8 inch black background. CARB will not issue the label but some county Farm Bureaus offer labels for their members.

If you are registering your AG vehicles for the first time and you do it before Dec. 31, there are two things to note. First, the form you pull up will be the 2014 reporting form, so ignore the Jan. 31, 2014, reporting deadline on it. Until CARB updates the form, just use the available form. Second, you will need to go back between Jan. 1 and Jan. 31 to report final 2014 mileage for newly registered vehicles.

Another option would be to wait until the 2015 form is available and register trucks for the first time after Jan. 1 but before Jan. 31, and you only have to report mileages once. For more information, contact CARB at 866-634-3735 or

If the AG annual mileage limits do not work for your operation, there are other options that are explained on the CFBF or CARB websites.

Another noteworthy change: The mileage for the low-use vehicle option was increased from 1,000 to 5,000 miles a year. If you register a vehicle with CARB as a low-use vehicle, you will not need to eventually replace it with a 2010 engine by 2023, as is required of most vehicles subject to the rule. The increase from 1,000 to 5,000 annual miles is only scheduled to last until 2020, when it drops back to 1,000. A big advantage of the low-use-vehicle option is you can purchase a truck at any time, as long as you keep it under the low-use mileage limit. Most of the other compliance options (including AG) require you to have owned the vehicle for several years. Each January, you can designate which trucks will use the low-use exemption for the year. You must report vehicle information and odometer readings by Jan. 31 of the compliance year or within 30 days of purchasing a vehicle.

CARB also added new areas where vehicles can use the NOx-exempt option. This option restricts where a vehicle can travel and requires a retrofit trap be installed by a certain date. Registration for this option closes on Jan. 31.

If none of the compliance options work for your trucks, there are two compliance schedules that will apply: one for light-duty (14,000 to 26,000 GVWR) and the other for heavy duty (26,000 pounds and heavier). The first compliance requirements for light-duty trucks begin Jan. 1, when any 1995 and older vehicle must be replaced with a newer vehicle. Depending on the age, many trucks over 26,000 GVWR are already required to comply, through replacement or retrofitting with soot traps.

See the or CARB websites for more details. The bottom line: Please use this opportunity to get into compliance by Jan. 31.

(Cynthia Cory is director of environmental affairs for the California Farm Bureau Federation. She may be contacted at

Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item.