T4F is a significant reduction in the EPA's allowable levels of exhaust emissions from diesel (not gasoline) engines. To meet T4F regulations, new diesel engines require significant modifications, including the installation of exhaust after-treatment devices. The result is fewer pollutants emitted by those engines and a cleaner environment.

Miller diesel engine-driven welder/generators affected by T4F include the Big Blue® 400, Big Blue® 400 Eco Pro, Big Blue® 500, Big Blue® 700 Duo Pro, Big Blue® Turbo and Big Blue® AirPak. Our new T4F products include the Big Blue® 800 Duo AirPak, Big Blue® 800 Duo Pro, and Big Blue® 500 Pro.

Each country has its own emissions rules, but only the U.S. is adopting T4F standards at this time. Canada has deferred implementation until January 1, 2019.

The EPA's first set of emissions regulations affecting diesel engines in the horsepower ranges used by Miller had an effective date of January 1, 1998. Since then, increasingly stringent emissions regulations have been implemented. T2 became effective in 2004 and was followed by T3/T4i in 2008. In each case, both Miller and the engine manufacturers made the modifications necessary to ensure full compliance.

Miller has prepared for the T4F changes not only by ensuring full compliance of affected diesel engine-driven welder/generators, but also by increasing the output capabilities of welder/generators with diesel engines rated under 25 horsepower, which meet a different level of Tier 4 EPA regulations. In improving the full line of Miller® diesel-powered welder/generators, we hope to make more options available to our customers and minimize the impact that the T4F regulations may have on them.