The U.S. Court of Appeals ruled to suspend the U.S. Environmental Protection Agency's (EPA) decision to lift limits on the number of manufacturered heavy duty vehicles, or glider trucks, that could be sold. 

This ruling comes after three environmental groups, the Environmental Defense Fund, Center for Biological Diversity and Sierra Club, petitioned the July 6 EPA decision not to enforce the previous Phase 2 emissions standards placed on glider kit trucks that would put a 300-unit production cap on glider production.

Glider kit trucks are rebuilt from salvaged diesel engines fitted into new frames, and they emit 450 times more diesel particulate matter and up to 40 times more smog-forming nitrogen oxides than new trucks on the market, according to the EPA’s own analysis.