Jeffrey Harmening

American Petroleum Institute Jeff Harmening

Jeffrey Harmening is manager, Engine Oil Licensing and Certification System, diesel exhaust fluid and Motor Oil Matters, American Petroleum Institute.

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How High-Quality Diesel Exhaust Fluid Keeps Trucks Running Smoothly

Here are some tips for drivers on the road and for shop owners to purchase high-quality DEF in a safe manner and to handle and store during warm weather months.