This section applies where exhaust emission testing is required, such as when applying the provisions of Sec. 1037.615. Note that for most vehicles, testing under this section is not required.
(a) Where applicable, measure emissions by testing the vehicle on a chassis dynamometer with the applicable test cycles. Each test cycle consists of a series of speed commands over time: variable speeds for the transient test and constant speeds for the cruise tests. None of these cycles include vehicle starting or warmup; each test cycle begins with a running, warmed-up vehicle. Start sampling emissions at the start of each cycle. The transient cycle is specified in appendix I to this part. For the 55 mph and 65 mph cruise cycles, sample emissions for 300 second cycles with constant vehicle speeds of 55.0 mph and 65.0 mph, respectively. The tolerance around these speed setpoints is 1.0 mph.
(b) Calculate the official emission result from the following equation:[GRAPHIC] [TIFF OMITTED] TR15SE11.011 Where: payload = the standard payload, in tons, as specified in Sec. 1037.705.w = weighting factor for the appropriate test cycle, as described in
paragraph (c) of this section.m = grams of CO2 emitted over the appropriate test cycle.D = miles driven over the appropriate test cycle.
(c) Apply weighting factors specific to each type of vehicle and for each duty cycle as described in the following table:
Table 1 to Sec. 1037.510--Weighting Factors for Duty Cycles----------------------------------------------------------------------------------------------------------------
55 mph cruise 65 mph cruise
Transient (%) (%) (%)----------------------------------------------------------------------------------------------------------------Vocational................................................ 42 21 37Vocational Hybrid Vehicles................................ 75 9 16Day Cabs.................................................. 19 17 64Sleeper Cabs.............................................. 5 9 86----------------------------------------------------------------------------------------------------------------
(d) For transient testing, compare actual second-by-second vehicle speed with the speed specified in the test cycle and ensure any differences are consistent with the criteria as specified in 40 CFR part 1066. If the speeds do not conform to these criteria, the test is not valid and must be repeated.
(e) Run test cycles as specified in 40 CFR part 86. For cruise cycle testing of vehicles equipped with cruise control, use the vehicle's cruise control to control the vehicle speed. For vehicles equipped with adjustable VSLs, test the vehicle with the VSL at its highest setting.
(f) Test the vehicle using its adjusted loaded vehicle weight, unless we determine this would be unrepresentative of in-use operation as specified in 40 CFR 1065.10(c)(1).
(g) For hybrid vehicles, correct for the net energy change of the energy storage device as described in 40 CFR 1066.501.