40 CFR § 610.20
General
June 9, 2020
The Administrator will employ the following criteria for evaluating the accuracy of fuel economy representations made with respect to retrofit devices:
(a) Device functional category;
(b) Device integrity;
(c) Operator interaction effects;
(d) Validity of test data;
(e) Evaluation of test data;
as these concepts are explained in §§610.21 through 610.25 respectively.