40 C.F.R. § 1037.320

Current through October 31, 2024

Section 1037.320 - Audit procedures for axles and transmissions

Selective enforcement audit provisions apply for axles and transmissions relative to the efficiency demonstrations of §§ 1037.560 and 1037.565 as specified in this section. The following provisions apply instead of 40 CFR 1068.415 through 1068.445 for the selective enforcement audit.

(a) A selective enforcement audit for axles or transmissions would consist of performing measurements with a production axle or transmission to determine mean power loss values as declared for GEM simulations, and running GEM over one or more applicable duty cycles based on those measured values. The axle or transmission is considered passing for a given configuration if the new modeled emission result for every applicable duty cycle is at or below the modeled emission result corresponding to the declared GEM inputs.

(b) Run GEM with the define vehicles to determine whether the transmission or axle family passes the audit.

(1) For transmission audits, run GEM for each applicable vehicle configuration and GEM regulatory subcategory identified in 40 CFR 1036.540 and for each vehicle class as defined in § 1037.140(g) using the applicable default engine map in appendix C of 40 CFR part 1036, the cycle-average fuel map in Table 1 of this section, the torque curve in Table 2 of this section for both the engine full-load torque curve and parent engine full-load torque curve, the motoring torque curve in Table 3 of this section, the idle fuel map in Table 4 of this section. For transmission testing, use the test transmission's gear ratios in place of the gear ratios defined in 40 CFR 1036.540 . Table 1 through Table 4 follow:

Table 1 to Paragraph (b)(1) of § 1037.320 -Transient Cycle-Average Fuel Map by Vehicle Class

Light HDV and medium HDV-spark-ignition					Light HDV and medium HDV-compression-ignition					Heavy HDV
Engine cycle work (kW·hr)	N/V (r/min)	Fuel mass (g)	Idle speed (r/min)	Idle torque (N·m)	Engine cycle work (kW·hr)	N/V (r/min)	Fuel mass (g)	Idle speed (r/min)	Idle torque (N·m)	Engine cycle work (kW·hr)	N/V (r/min)	Fuel mass (g)	Idle speed (r/min)	Idle torque (N·m)
3.5404	2.8739	1109.31	600.5	37.997	3.3057	2.3317	919.01	750.3	36.347	11.4255	2.3972	2579.58	600.7	89.658
3.6574	3.0198	1153.35	600.4	37.951	3.3822	2.5075	982.53	750.2	36.461	11.6112	2.2432	2591.08	601.2	90.428
3.8119	3.0370	1188.66	600.2	37.956	3.4917	2.5320	998.64	750.2	36.608	12.5052	2.1620	2763.28	602.4	92.014
4.0121	3.1983	1250.76	600.1	38.153	3.6087	2.6181	1036.34	750.2	36.734	17.7747	2.5195	3835.77	602.2	91.780
5.5567	3.1325	1585.32	604.6	56.535	5.2397	2.5050	1354.33	753.0	51.992	18.4901	2.4155	3994.29	603.5	93.724
5.6814	3.2956	1639.08	604.0	56.549	5.3153	2.7289	1417.20	751.9	51.488	20.1904	2.3800	4374.06	605.1	96.340
5.8720	3.3255	1686.14	602.5	56.234	5.4112	2.6689	1416.75	751.3	51.280
6.1774	3.4848	1773.39	601.7	56.038	5.5590	2.7231	1450.67	751.0	51.254

Table 2 to Paragraph (b)(1) of § 1037.320 -Full-Load Torque Curves by Vehicle Class

Light HDV and medium HDV- spark-ignition		Light HDV and medium HDV- compression-ignition		Heavy HDV
Engine speed (r/min)	Engine torque (N·m)	Engine speed (r/min)	Engine torque (N·m)	Engine speed (r/min)	Engine torque (N·m)
600	433	750	470	600	1200
700	436	907	579	750	1320
800	445	1055	721	850	1490
900	473	1208	850	950	1700
1000	492	1358	876	1050	1950
1100	515	1507	866	1100	2090
1200	526	1660	870	1200	2100
1300	541	1809	868	1250	2100
1400	542	1954	869	1300	2093
1500	542	2105	878	1400	2092
1600	542	2258	850	1500	2085
1700	547	2405	800	1520	2075
1800	550	2556	734	1600	2010
1900	551	2600	0	1700	1910
2000	554			1800	1801
2100	553			1900	1640
2200	558			2000	1350
2300	558			2100	910
2400	566			2250	0
2500	571
2600	572
2700	581
2800	586
2900	587
3000	590
3100	591
3200	589
3300	585
3400	584
3500	582
3600	573
3700	562
3800	555
3900	544
4000	534
4100	517
4200	473
4291	442
4500	150

Table 3 to Paragraph (b)(1) of § 1037.320 -Motoring Torque Curves by Vehicle Class

Light HDV and medium HDV- spark-ignition		Light HDV and medium HDV- compression-ignition		Heavy HDV
Engine speed (r/min)	Engine torque (N·m)	Engine speed (r/min)	Engine torque (N·m)	Engine speed (r/min)	Engine torque (N·m)
700	-41	750	-129	600	-98
800	-42	907	-129	750	-121
900	-43	1055	-130	850	-138
1000	-45	1208	-132	950	-155
1100	-48	1358	-135	1050	-174
1200	-49	1507	-138	1100	-184
1300	-50	1660	-143	1200	-204
1411	-51	1809	-148	1250	-214
1511	-52	1954	-155	1300	-225
1611	-53	2105	-162	1400	-247
1711	-56	2258	-170	1500	-270
1811	-56	2405	-179	1520	-275
1911	-57	2556	-189	1600	-294
2011	-57			1700	-319
2111	-58			1800	-345
2211	-60			1900	-372
2311	-65			2000	-400
2411	-81			2100	-429
2511	-85
2611	-87
2711	-88
2811	-89
2911	-91
3011	-91
3111	-96
3211	-96
3311	-97
3411	-98
3511	-99
3611	-104
3711	-105
3811	-108
3911	-108
4011	-111
4111	-111
4211	-115
4291	-112

Table 4 to Paragraph (b)(1) of § 1037.320 -Engine Idle Fuel Maps by Vehicle Class

Light HDV and medium HDV-spark-ignition			Light HDV and medium HDV-compression-ignition			Heavy HDV
Engine speed (r/min)	Engine torque (N·m)	Fuel mass rate (g/s)	Engine speed (r/min)	Engine torque (N·m)	Fuel mass rate (g/s)	Engine speed (r/min)	Engine torque (N·m)	Fuel mass rate (g/s)
600	0	0.4010	750	0	0.2595	600	0	0.3501
700	0	0.4725	850	0	0.2626	700	0	0.4745
600	100	0.6637	750	100	0.6931	600	100	0.6547
700	100	0.7524	850	100	0.7306	700	100	0.8304

(2) Follow the procedure in paragraph (b)(1) of this section for axle audits, but cover the range of tire sizes by using good engineering judgment to select three representative tire sizes for each axle ratio for each vehicle configuration instead of using the tire size determined in 40 CFR 1036.540 .

(3) The GEM "Default FEL CO₂ Emissions" result for each vehicle configuration counts as a separate test for determining whether the family passes the audit. For vocational vehicles, use the GEM "Default FEL CO₂ Emissions" result for the Regional subcategory.

(c) If the initial axle or transmission passes, the family passes and no further testing is required. If the initial axle or transmission does not pass, select two additional production axles or transmissions, as applicable, to perform additional tests. Note that these could be different axle and transmission configurations within the family. These become official test results for the family. Use good engineering judgment to use the results of these tests to update the declared maps for the axle or transmission family. For example, if you fail the audit test for any of the axles or transmissions tested, the audit result becomes the declared map. This may also require revising any analytically derived maps.

40 C.F.R. §1037.320

86 FR 34464 , June 29, 2021, as amended at 88 FR 4639 , Jan. 24, 2023

86 FR 34464, 6/29/2021; as amended at 88 FR 4639, 3/27/2023