How does checking at two speeds benefit vehicle emission testing?

Checking vehicle emissions at two different speeds is beneficial because it allows inspectors to assess the vehicle's performance across a range of operational conditions. Different speeds can influence how an engine performs and how effectively it controls emissions. For instance, a vehicle may operate efficiently under certain conditions but may struggle to control emissions under others.

By testing at two speeds, inspectors can identify specific issues that may not be apparent when testing at just one speed. This comprehensive approach helps ensure that the vehicle meets emissions standards throughout its operating range, thus contributing to a more accurate evaluation of its environmental impact. Such a method also benefits regulatory compliance and helps ensure that vehicles are maintained properly for optimal emissions control.