86.1432—Vehicle preparation.
(a)
The test conditions to be employed in the CST procedure must be selected from the applicable options specified in table O-96-1 or table O-96-2 of § 86.1430(b). The fuel tank must be fitted, as required, to accommodate a fuel drain at the lowest point possible in the tank(s) as installed on the vehicle.
(b) Fuel tank drain and fill, or transient test procedure—
(1) CST performed as a stand-alone procedure.
For the first CST compliance pathway performed as a stand-alone procedure on a particular test vehicle, the fuel tank(s) must be filled to approximately the prescribed “tank fuel volume” (as defined in § 86.082-2) with the specified test fuel. For the cold temperature compliance pathway, the temperature of the fuel prior to its delivery to the fuel tank must be less than or equal to 60 °F (16 °C). If the existing fuel in the fuel tank(s) does not meet the specifications contained in §§ 86.1413 and 86.1430(b), the existing fuel must be drained prior to the fuel fill as specified above. Other refueling during a CST may not be performed. Draining and refueling between successive CSTs is allowed and is required prior to any CST for which the specified fuel is different than that existing in the tank(s). Any soak or operation that follows this step, until the conclusion of the CST sequence, must occur at an ambient temperature that is within the allowable temperature range described in § 86.1430(c).
(2) CST performed in sequence with other confirmatory testing.
Certain complete confirmatory test procedures, as indicated in paragraphs (b)(2) (i) and (ii) of this section, may be substituted for the vehicle preparation steps described in paragraph (b)(1), (c), and (d) of this section. If the vehicle is to be subjected to one or more of these other confirmatory test procedures, the vehicle is prepared in accordance with the applicable complete procedures from the point of fuel drain and fill.
(i) Manufacturer's data submittal.
The only test procedure that the manufacturer may select to substitute for paragraphs (b)(1), (c)(1), and (d)(1) of this section for the purposes of its data submittal is the Cold CO Test Procedure, performed in accordance with subpart C of this part.
(ii) Testing by the Administrator.
The complete confirmatory test sequences that the Administrator may select to substitute for paragraph (b)(1) of this section are listed in paragraphs (b)(2)(ii) (A) through (C) of this section.
(A)
Federal Test Procedure for exhaust emissions (except when performing evaporative test sequence) or for fuel economy testing, in accordance with subpart B of this part.
(B)
Highway Fuel Economy Test Procedure, in accordance with part 600 of this chapter (which must follow a Federal Test Procedure).
(c) Soak—
(1) Manufacturer's data submittal.
A vehicle soak prior to the wait time is optional if the CST sequence is performed as a stand-alone procedure. If the manufacturer elects to perform a Cold CO Test Procedure in conjunction with the CST as permitted in paragraph (b)(2) of this section, the soak and subsequent warmup are not conducted, and instead the procedure must move directly to the wait time step described in § 86.1437(b). If the test vehicle undergoes a soak period, it must be maintained at an ambient temperature within the temperature range specified in § 86.1430(c), for a period not to exceed 36 hours in duration, except as provided in paragraph (d)(1) of this section. Ambient temperature during soak periods must remain within the appropriate temperature range for the selected test option.
(2) Testing by the Administrator.
(i)
The test sequence may proceed directly to the wait time step described in § 86.1438(b) within 60 seconds of the end of vehicle operation conducted in accordance with paragraph (b)(2) of this section.
(ii)
Optionally, the test vehicle may soak at an ambient temperature within the temperature range specified in § 86.1430(c), for a period up to 36 hours in duration, except as provided in paragraph (d)(2) of this section. If the Administrator opts to soak the test vehicle, warmup operation must be performed as described in paragraph (d)(2) of this section.
(d) Warmup operation—
(1) Manufacturer's data submittal.
Warmup operation is optional. Warmup consists of loaded operation over the first 505 seconds of the UDDS (in accordance with § 86.115 and appendix I to this part), or optionally, if the soak period has exceeded 36 hours, a full UDDS. Warmup operation must occur within the specific ambient temperature range for the selected test option, as given in table O-96-1 of § 86.1430.
(2) Testing by the Administrator.
Warmup operation is performed if no transient operation of the type specified in § 86.1432(b)(2) is performed prior to the wait time, or if the optional soak exceeds 60 seconds. Warmup operation consists of, at a minimum, loaded operation over the first 505 seconds of the UDDS (in accordance with § 86.115 and appendix I to this part), or, if the soak period has exceeded 36 hours, a full UDDS. Warmup operation must occur within the specific ambient temperature range for the selected test option, as given in table O-96-2 of § 86.1430, except as specified in paragraphs (e)(2)(i) and (ii) of this section. Warmup operation must proceed immediately to the wait time step at § 86.1438(b).
(i)
For moderate temperature testing utilizing Cold CO fuel only, the ambient temperature may not exceed 80 °F (27 °C) during warmup operation, or any of the succeeding steps in the CST sequence.
(ii)
For the cold temperature pathway only, warmup operation must occur not only within the specific ambient temperature range indicated in table O-96-2 of § 86.1430, but must also occur within 5 °F (3 °C) of the selected test temperature.