§ 86.1824-08 Durability demonstration procedures for evaporative emissions.

This section describes durability demonstration procedures for evaporative emissions. Eligible small-volume manufacturers or small-volume test groups may optionally meet the requirements of §§ 86.1826 and 86.1838 instead of the requirements of paragraphs (a) through (j) of this section. A separate durability demonstration is required for each evaporative/refueling family.

(a) Durability program objective. The durability program must predict an expected in-use emission deterioration rate and emission level that effectively represents a significant majority of the distribution of emission levels and deterioration in actual use over the full useful life of candidate in-use vehicles of each vehicle design which uses the durability program. This requirement applies for all SHED-based measurements except the bleed emission test. The standard for bleed emissions applies for the full useful life, but manufacturers do not need to establish deterioration factors for bleed emissions. The requirements of this section do not apply for spitback or leak standards.

(b) Required durability demonstration. Manufacturers must conduct a durability demonstration which satisfies the provisions of either paragraph (c), (d), or (e) of this section.

(c) Whole vehicle evaporative durability demonstration. (1) Mileage accumulation must be conducted using the SRC or any road cycle approved under the provisions of § 86.1823-08(e)(1).

(2) Mileage accumulation must be conducted for either:

(i) The applicable full useful life mileage period specified in § 86.1805, or

(ii) At least 75 percent of the full useful life mileage. In which case, the manufacturer must calculate a df calculated according to the procedures of paragraph (f)(1)(ii) of this section, except that the DF must be based upon a line projected to the full-useful life mileage using the upper 80 percent statistical confidence limit calculated from the emission data.