"L.A. Metro Buses with CWI Near-Zero NG Engine are Super Clean"

"[A] study found that a Los Angeles County Metropolitan Transportation Authority (Metro) bus equipped with an ultra-low emission natural gas engine performs significantly cleaner than its certification standards across all duty cycles.

“We have tested two of the ISL G near-zero 8.9 liter engines, one in a refuse hauler and one in a Metro bus. In both cases, the NOx emissions were surprisingly low and 99 percent cleaner than the current standard and 99.96 percent cleaner than the 2004 standard,” said Kent Johnson, associate research engineer for CE-CERT and lead researcher on this study.

Highlights of the study include:

• The engine tested below Environmental Protection Agency (EPA) NOx (smog-forming) emissions certification level of 0.2g/bhp-hr.
  
• The engine tested below the California Air Resources Board voluntary limit of 0.02 /bhp-hr. This is the only engine to meet the California standard.
  
• Emissions for some driving patterns, such as stop-and-go traffic were even lower still.
  
• In some driving conditions the bus tested as low as 0.0007g/bhp-hr, or practically zero emissions.

Additional info, including a link to the study's final report can be found in this article.