In the United States, emissions warranties for new vehicles are structured in tiers, with durations that vary by component and program. The typical federal coverage includes a short basic period, a longer defect period, and a long-term performance guarantee, while some states—most notably California—may provide extended protection. The exact terms depend on the model year, vehicle, and jurisdiction.
What the standard federal coverage looks like
Emissions warranties are designed to ensure emission-related parts function properly and do not cause excessive pollution. Here is the standard breakdown you will commonly see on new cars sold in the United States:
- Basic Emissions Warranty: 2 years or 24,000 miles, covering defects in emission-related parts that would cause emissions to exceed standards.
- Emissions Defect Warranty: 3 years or 50,000 miles, covering defects in emission-related components that cause emissions failures.
- Emissions Performance Warranty: 8 years or 80,000 miles, covering major emission-control components that fail to perform as intended due to a defect, allowing repair or replacement to restore emissions performance.
The specific list of components included in each category is defined by the EPA and the vehicle's manufacturer, and can vary by model year. Always consult the vehicle's warranty booklet for the exact coverage and eligible components.
State variations and how to check your coverage
Emissions warranty terms can extend beyond federal requirements, with state-level programs offering longer protection in some cases. California, for example, has its own rules administered by the California Air Resources Board, and several other states align with those standards or offer similar extended coverage.
- Check your state's air quality or environmental agency for current emissions-warranty terms applicable to your vehicle's model year.
- Review your owner's manual and the "Emissions Warranty" section for model-specific durations and covered parts.
- If you believe a covered emissions part is failing, contact your dealer or an authorized repair facility to determine eligibility and initiate a warranty claim.
Be aware that the warranty may begin on the vehicle’s in-service date and can expire at a mileage or time threshold, even if the vehicle has low annual mileage. Claims must be filed within the coverage window.
Summary
Emissions warranty durations vary by category and jurisdiction. The typical federal framework offers 2 years/24,000 miles for basic coverage, 3 years/50,000 miles for defect coverage, and up to 8 years/80,000 miles for major emission components. State programs, especially California, may extend these terms. Always verify the exact terms in your owner's manual and with your state authorities or dealer.