StacksVerified U.S. regulatory reference

49 CFR Part 531, Appendix A

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov

Assume a hypothetical manufacturer (Manufacturer X) produces a fleet of domestic passenger automobiles in MY 2012 as follows:

Model typeDescriptionActualmeasured fueleconomy(mpg)Volume
GroupCarline nameBasic engine(L)Transmissionclass
1PC A FWD1.8A5 | 2-door sedan | 34 | 1,500
2PC A FWD1.8M6 | 2-door sedan | 34.6 | 2,000
3PC A FWD2.5A6 | 4-door wagon | 33.8 | 2,000
4PC A AWD1.8A6 | 4-door wagon | 34.4 | 1,000
5PC A AWD2.5M6 | 2-door hatchback | 32.9 | 3,000
6PC B RWD2.5A6 | 4-door wagon | 32.2 | 8,000
7PC B RWD2.5A7 | 4-door sedan | 33.1 | 2,000
8PC C AWD3.2A7 | 4-door sedan | 30.6 | 5,000
9PC C FWD3.2M6 | 2-door coupe | 28.5 | 3,000
Total||| 27,500

Note to Table I to this appendix: Manufacturer X's required fleet average fuel economy standard level would first be calculated by determining the fuel economy targets applicable to each unique model type and footprint combination for model type groups 1-9 as illustrated in Table II to this appendix.

Manufacturer X calculates a fuel economy target standard for each unique model type and footprint combination.

Model typeDescriptionBase tire sizeWheelbase(inches)Track width F&Raverage(inches)Footprint(ft2)VolumeFuel economy target standard(mpg)
GroupCarline nameBasicengine (L)Transmission class
1PC A FWD1.8A52-door sedan205/75R1499.861.2 | 42.4 | 1,500 | 35.01
2PC A FWD1.8M62-door sedan215/70R1599.860.9 | 42.2 | 2,000 | 35.14
3PC A FWD2.5A64-door wagon215/70R1510060.9 | 42.3 | 2,000 | 35.08
4PC A AWD1.8A64-door wagon235/60R1510061.2 | 42.5 | 1,000 | 35.95
5PC A AWD2.5M62-door hatchback225/65R1699.659.5 | 41.2 | 3,000 | 35.81
6PC B RWD2.5A64-door wagon265/55R18109.266.8 | 50.7 | 8,000 | 30.33
7PC B RWD2.5A74-door sedan235/65R17109.267.8 | 51.4 | 2,000 | 29.99
8PC C AWD3.2A74-door sedan265/55R18111.367.8 | 52.4 | 5,000 | 29.52
9PC C FWD3.2M62-door coupe225/65R16111.367.2 | 51.9 | 3,000 | 29.76
Total||||27,500

Note to Table II to this appendix: With the appropriate fuel economy targets determined for each unique model type and footprint combination, Manufacturer X's required fleet average fuel economy standard would be calculated as illustrated in Figure 1 to this appendix.

Note to Figure 2 to this appendix: Since the actual fleet average fuel economy performance of Manufacturer X's fleet is 32.0 mpg, as compared to its required fleet fuel economy standard of 31.6 mpg, Manufacturer X complied with the CAFE standard for MY 2012 as set forth in § 531.5(c).