Section 86.436-78 - Additional service accumulation(a) Additional service up to the useful life will be accumulated under the same conditions as the initial service accumulation.(b) New deterioration lines will be generated using all applicable test points up to the useful life. The same procedures for determining the original deterioration lines will be used.(d) To qualify for certification: (1) The full life emission test results must be at or below the standards in this subpart; and(2) The deterioration line must be below the standard at the minimum test distance and the useful life, or all points used to generate the line, must be at or below the standard.(e) If the vehicle is unable to complete the total distance due to engine mechanical failure, certification will be granted if:(1) The mechanical failure was anticipated, § 86.428 , and(2) A new deterioration line calculated using the procedure described in § 86.436-78(b) is below the standard at the minimum test distance and at the useful life, and,(3) The results of the half life emission tests, when adjusted by the new deterioration factors, are below the standards.42 FR 1126, Jan. 5, 1977, as amended at 49 FR 48139, Dec. 10, 1984; 86 FR 34367 , June 29, 2021