California Air Resources Board

                                                                                                                                                                                                < BACK TO CURRENT ACTIVITIES

CARB has a need to collect more data to characterize emissions from Class 2b-3 vehicles (8,501 lbs.-14,000 lbs. gross vehicle weight rating (GVWR)) that fall under the light heavy-duty (LHD) category. Under California’s EMissions FACtor inventory model (EMFAC), these vehicles are characterized as Light Heavy-Duty 1 (LHD1) (GVWR: 8,501 lbs. – 10,000 lbs.) and Light Heavy-Duty 2 (LHD2) (GVWR: 10,001 lbs. – 14,000 lbs.). These two vehicle classes make up about 4 percent of the California on-road fleet and are responsible for about 17 percent of statewide nitrogen oxides (NO_x) and about 18 percent of statewide on-road vehicle fine particulate matter (PM_2.5) emissions.

Considering LHD1 and LHD2 trucks will be part of CARB’s technology forcing regulations (e.g., CA Phase 2 GHG standards, Advanced Clean Cars II (ACC II) and Advanced Clean Truck (ACT) regulations), testing this class of vehicles is necessary to assess in-use emissions from light heavy-duty engines that are powered by gasoline and diesel under different driving conditions. In 2017, CARB conducted a research project to solicit and procure twelve diesel and gasoline light heavy-duty vehicles to collect emissions data that was used to update EMFAC.

Starting in 2023, CARB staff will be conducting a new LHD surveillance program to collect emissions data from this class of vehicles. The collected test data will be used to evaluate emission rates from chassis dynamometer testing and portable emissions measurement systems (PEMS) testing. A selected test vehicle from each class will be tested on-road with PEMS with and without towing a trailer. Additional testing over arterial and freeway driving cycles will help evaluate and update the model’s light-duty vehicle speed correction factors. Particulate matter (PM) and speciated emissions data will be collected to support air quality planning.

If you have questions, please contact the LDVSP Project Engineer, Steven Magbuhat (steven.magbuhat@arb.ca.gov) at (951) 542-3275 or Section Manager, Satya Sardar (satya.sardar@arb.ca.gov) at (951) 542-3376.