Appendix XV to Part 86 - Procedure for Determining an Acceptable Exhaust Regeneration Durability-Data Test Schedule for Diesel Cycle Vehicles Equipped With Periodically Regenerating Trap Oxidizer Systems Certifying to the Provisions of Part 86, Subpart R

Link to an amendment published at 79 FR 23746, Apr. 28, 2014.

1. Select exhaust system mileage test points for proposed (prop) schedule.

2. Calculate the sums of the squares corrected to the mean of the system mileages at the proposed test points:

Aprop = [Σ(Xp)2 − ((ΣXp)2 / Np))prop

Xp = Individual mileages at which the vehicle will be tested.

Np = Total number of tests (including before and after maintenance tests).

3. The exhaust system mileage tests points at 5,000, 25,000, 50,000, 75,000, and 100,000 miles will be designated as the standard (std) test schedule.

4. Calculate the sums of square corrected to the mean of the standard tests schedule:

Bstd = [Σ(Xs)2 − ((ΣXs)2 / Ns))std

Xs = Individual mileages at which the vehicle will be tested.

Ns = Total number of regeneration emission tests.

5. Refer to table I and determine tp at (Np − 2)prop degrees of freedom and ts at (Ns − 2)std degrees of freedom.

6. If (Aprop)1/2 ≥tp / ts × (Bstd)1/2 the proposed plan is acceptable.

Table I to Appendix XV

Degrees of freedom (N-2)	t
1	6.314
2	2.920
3	2.353
4	2.132
5	2.015
6	1.943
7	1.895
8	1.860
9	1.833
10	1.812
11	1.796
12	1.782
13	1.771
14	1.761
15	1.753

[62 FR 31264, June 6, 1997]