StacksVerified U.S. regulatory reference

40 CFR §610.23

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
The device will also be evaluated with respect to:
  1. (a)The degree of sensitivity of device effectiveness to variances in installation, operation and maintenance;
  2. (b)The adequacy of manufacturer-furnished instructions for minimizing variances in installation, operation and maintenance;
  3. (c)The extent to which device installation or use, or the effects of such installation or use, relate to Federal emission control regulations;
  4. (d)Effects on the performance, safety, or occupant comfort of the retrofitted vehicle, and on that of other vehicles; and
  5. (e)The relationship between total cost of ownership of the device (purchase price plus maintenance costs) and the cost savings realizable from its fuel economy effects.