Frequent Questions

Where can I find information on the Tier 2 vehicle and gasoline sulfur standards?

For information on the Tier 2 and Tier 3 programs and gasoline sulfur standards, see Gasoline Sulfur.

Also see:


  • For further information on the Tier 2 standards, contact David Good: 734-214-4450,
  • For questions on fuels registration, reporting and compliance, contact the EPA Fuels Program.

For information on sulfur and diesel fuel:

Clean Diesel Fuel Alliance Information Center: Answers to Frequently Asked Questions About Ultra Low Sulfur Diesel (ULSD) fuel. Exit 

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