Code of Federal Regulations Title 40. Protection of Environment § 40.610.25 Evaluation of test data

(a) Vehicle applicability;

(b) Dependence of device effects upon vehicle type;

(c) Device effects on fuel economy, and on emissions, with statistical or other caveats as established by the data base;

(d) Definition of claims which can be made based on the available data;  and

(e) Substantiation of specified claims made by the manufacturer.