Bill O'Ryan, American Petroleum Institute

Website: https://www.api.org/
About Bill O'Ryan, American Petroleum Institute: Bill O’Ryan is director of the Engine Oil Licensing and Certification System (EOLCS) and Diesel Exhaust Fluid (DEF) Certification Programs at the American Petroleum Institute (API). He has worked in the transportation lubricants industry for over 30 years and joined the American Petroleum Institute (API) in 2022. His background includes additive package development, engine and driveline testing. Bill has oversight responsibility for the Aftermarket Audit Program (AMAP), an annual program in which thousands of engine oil and DEF samples are purchased in the marketplace around the globe and tested to ensure conformance with required specifications.

Posts by Bill O'Ryan, American Petroleum Institute

PC-12 approval introduces API CL-4 and FB-4 service donuts for next-generation engine performance

By Bill O'Ryan, American Petroleum Institute - April 28, 2026

The heavy-duty trucking industry is entering an important period of transition as new engine technologies and emissions regulations impact operational requirements. The formal approval of

Fleet and mobility: API PC-12 advances toward finalization as industry prepares for 2027

By Bill O'Ryan, American Petroleum Institute - February 17, 2026

The development of the American Petroleum Institute’s Proposed Category 12 (PC-12) heavy-duty engine oil specification has entered its final stages, representing a significant milestone for

2027 EPA emissions rule for heavy-duty trucks expands warranty and service life requirements

By Bill O'Ryan, American Petroleum Institute - November 6, 2025

In late 2022, the U.S. Environmental Protection Agency (EPA) finalized a rule titled “Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicle