49 CFR 538.5 – Minimum driving range
(a) The minimum driving range that a passenger automobile must have in order to be treated as a dual fueled automobile pursuant to 49 U.S.C. § 32901(c) is 200 miles when operating on its nominal useable fuel tank capacity of the alternative fuel, except when the alternative fuel is electricity or compressed natural gas. Beginning model year 2016, a natural gas passenger automobile must have a minimum driving range of 150 miles when operating on its nominal useable fuel tank capacity of the alternative fuel to be treated as a dual fueled automobile, pursuant to 49 U.S.C. § 32901(c)(2).
(b) The minimum driving range that a passenger automobile using electricity as an alternative fuel must have in order to be treated as a dual fueled automobile pursuant to 49 U.S.C. § 32901(c) is 7.5 miles on its nominal storage capacity of electricity when operated on the EPA urban test cycle and 10.2 miles on its nominal storage capacity of electricity when operated on the EPA highway test cycle.