Potential Amendments to the Off-Road New Diesel Engine Emission Standards: Tier 5 Criteria Pollutants and CO2 Standards
CARB staff is starting work on potential amendments to the off-road diesel engine standards, in what we are calling the Tier 5 rulemaking. The Tier 5 rulemaking aims to reduce oxides of nitrogen (NOx) and particulate matter (PM) emissions from new, off‑road compression-ignition (CI) engines compared to what is allowed by today’s Tier 4 final emission standards.
More about this program
Keep up to date with the latest information regarding the Tier 5.