Smog rating.
Smog rating. Establish a rating for exhaust emissions other than CO2 based on the applicable emission standards for the appropriate model year as shown in Tables 1 through 3 of this section. Unless specified otherwise, use the California emission standards to select the smog rating only for vehicles not certified to any EPA standards. For Independent Commercial Importers that import vehicles not subject to Tier 2 or Tier 3 emission standards, the vehicle's smog rating is 1. Similarly, if a manufacturer certifies vehicles to emission standards that are less stringent than all the identified standards for any reason, the vehicle's smog rating is 1. If EPA or California emission standards change in the future, we may revise the emission levels corresponding to each rating for future model years as appropriate to reflect the changed standards. If this occurs, we would publish the revised ratings as described in 600.302-12(k), allowing sufficient lead time to make the changes; we would also expect to initiate a rulemaking to update the smog rating in the regulation.