California Air Resources Board

• Small off-road engine (SORE) regulations apply to spark-ignition engines 25 hp and below, used in most lawn and garden equipment
• 2021 amendments to the SORE regulations became effective January 1, 2023. Emission standards for smog-forming emissions from most new engines are zero starting in model year 2024. Emission standards for smog-forming emissions from portable generators and large pressure washers are more stringent starting in model year 2024 and zero in model year 2028
• SORE regulations do not have requirements for equipment owners
• 2021 amendments do not apply to model year 2022 or earlier equipment

Purpose of the SORE Regulations

The SORE regulations are intended to reduce emissions from small off-road equipment and transition such equipment to zero-emission equipment (ZEE). Deployment of ZEE is key to attain ambient air quality standards and protect the health and welfare of all California residents. The SORE regulations also help ensure that engines sold and used in California will comply with exhaust and evaporative emission standards throughout their lifetime.

Model Year 2024 Emission Standards for New SORE

The SORE regulations set emission standards for smog-forming pollutants to zero for all new engines except for generator and large pressure washer engines beginning with model year 2024. The regulations set more stringent emission standards for generator and large pressure washer engines beginning with model year 2024. Manufacturers may use emission reduction credits to certify engines until all credits are used or expire.

Applicability of the SORE Regulations

The new emission standards apply to new engines. The SORE regulations do not prohibit possession, use, or repair of existing CARB-compliant SORE equipment. California residents and businesses may continue using their CARB-compliant SORE equipment, and repair it, until the end of its life. Stores may continue to sell any engines and equipment that were manufactured under valid CARB certifications. More on applicability may be found here. Engines that use diesel fuel and engines that are used in stationary equipment are not subject to the SORE regulations. Federal law preempts states from regulating new engines which are used in construction equipment or vehicles or used in farm equipment or vehicles, and which are smaller than 175 horsepower. More information may be found here.

Effects of the Amendments

Some users will see savings when using ZEE. Emission modeling shows that the amendments to the SORE regulations will achieve major reductions in smog-forming pollutant emissions from SORE. These emission reductions will result in significant health benefits for Californians.