CARB reminded them in a statement last week.
The reg affects dry-van and refrigerated trailers 53 feet long or longer. Vans must use federal SmartWay-approved equipment to lower fuel use by at least 5 percent; reefers must save at least 4 percent, and their transport refrigeration units, or TRUs, must meet separate requirements for lower exhaust emissions.
"Fleets have two options to comply with California's Tractor-Trailer Greenhouse Gas regulation: either be in compliance by January 1, 2013, or take advantage of an option which allows a longer compliance phase-in," CARB said. "To take advantage of the longer phase-in, large fleets (with 21 or more trailers) must submit a compliance plan to the California Air Resources Board by July 1, 2011.
"The plan includes a list of trailers in the fleet, and the scheduled percentage of trailers to be brought into compliance each year. The phase-in option allows fleets up to five years from 2011 through 2015 to phase-in compliance for their California-bound trailers."
Instructions on how to prepare and submit your plan can be found in the Large Fleet Compliance fact sheet at: http://www.arb.ca.gov/largefleetplan.
Aerodynamic improvers are getting CARB's initial focus, with low-rolling-resistance tires required later. All are described on the CARB website, which has carried information on the rules for more than a year.
Most fleets are meeting the rules by using side skirts, said Sean Graham of Freightwing, one manufacturer supplying such devices. Some less-effective skirts need other devices, like gap-plugging fairings, to add up to the minimum requirement.
But "advanced aerodynamic fairings that meet the 5 percent requirement on their own seems the favorite," he said. "Ours was tested under the TMC-SAE J1321 method at 7 percent," which means no other devices would be needed on a trailer so equipped.
UPDATE -- CARB has extended the deadline to August 1.