These documents show engine family boxes that group engine families with similar characteristics (i.e., the emissions standards that the engines were built to) for current and past model years.

Manufacturers should review this information as part of the Requirements for Clean Diesel Verification.

• Family Groups for Highway Engines (PDF)(2 pp, 83 K, May 2006)
• Family Groups for Non-Road Engines (PDF)(4 pp, 111 K, May 2006)