Commentary: Be prepared for changes to the state diesel truck rule

Issue Date: October 30, 2013
By Cynthia Cory
Cynthia Cory
The state Air Resources Board has decided to reopen registration for agricultural trucks that qualify for the “AG” sticker as shown in photo.

Never say never.

Although the deadline to register as an "AG" truck is long past, the California Air Resources Board will now allow those that missed the April 29, 2011, deadline to register. CARB decided last week to provide another registration opportunity for truck owners. The requirement that you owned the truck by Jan. 1, 2009, still applies and, once registered, the truck must stay under specific mileage thresholds, but it sure beats having to replace the truck or retrofit it with a soot trap.

A handful of changes were presented on Oct. 24 at CARB in front of a full auditorium. The specific details will be published in a compliance enforcement advisory in the next couple of weeks. Among other proposals, CARB discussed increasing the low-use vehicle threshold from 1,000 miles a year to 5,000 miles a year. So, if you have trucks that you drive less than 5,000 miles annually but were bought after Jan. 1, 2009, this category might be helpful.

CARB will possibly adjust NOx Exempt Area provisions by changing the regions covered and compliance deadlines. Funding opportunities specifically for small fleets and log trucks will be made available. CARB will also reopen registration for the low-mileage construction provision.

We will disseminate the details as soon as CARB provides them publicly. In the meantime, please be aware of these changes, in case you were about to replace any vehicles. Use the California Farm Bureau Federation website for background on the truck rule, at Once you get to the main website, find the Issues and Regulations link on the left side. Under this link, we have listed the truck rule information under both Air Quality and Transportation categories. All the basic truck rule information is provided, as well as a link to register your trucks electronically with CARB. Although you can also download a form and do it by mail, you might experience fewer problems if you register electronically, as you do not have to rely on a third party inputting your data correctly when they receive it at CARB.

The truck rule is too complex to include all the details in this article. So please, use and bookmark the CFBF website on your computer and monitor it for this and other rules and regulations that might apply to your operation. These links are updated regularly, as the truck rule information will be once we have the final compliance advisory.

As a quick reminder, the diesel truck and bus rule applies to any on-road diesel vehicle over 14,000 Gross Vehicle Weight Rating. There are two compliance schedules: one for light-duty trucks 14,000 to 26,000 GVWR, and one for heavy-duty trucks, those 26,000 GVWR and larger. The first compliance requirements for light-duty trucks begin Jan. 1, 2015, when any 1995 and older vehicle must be replaced with a newer vehicle. Depending on the age, many trucks heavier than 26,000 GVWR are already required to comply through replacement or retrofitting with soot traps. See the website for these details.

Many trucks owned by farming businesses or log harvest operations can qualify for a compliance extension, if they are used exclusively for growing or harvesting crops for the primary purpose of making a profit or to deliver the harvested crop. These trucks must have been owned by Jan. 1, 2009, and must stay below annual mileage limits to qualify for the extension.

Compliance is extended until 2023 if the vehicle travels less than 10,000 miles annually. If more mileage is needed, vehicles can be driven as shown in the chart below, based on their engine model year, until Jan. 1, 2017.

Engine Model Year

Annual Limit


2006 or newer

25,000 miles

1996 to 2005

20,000 miles

1995 and older

15,000 miles

By 2017, these vehicles must comply with any applicable PM filter and replacement requirements, just as non-agricultural vehicles must. Starting in 2017, only vehicles that are operated less than 10,000 miles every year can continue to have the extension until Jan. 1, 2023, if they continue to operate less than 10,000 miles per year. Vehicles that exceed the mileage limits in any year must comply with the general requirements that other trucks do.

So, the word must be spread: The AG registration for diesel trucks is back open. If you are eligible, you should not wait, but register now using the CFBF website link or go straight to CARB at

Stay tuned, as CFBF will continue to make details available once they are released by the Air Resources Board.

(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.