This section describes the emission testing you must perform to show compliance with respect to the greenhouse gas emission standards in subpart B of this part, and to determine any input values from §§1037.515 and 1037.520 that involve measured quantities.

(a) Select emission-data vehicles that represent production vehicles and components for the vehicle family consistent with the specifications in §§1037.205(o), 1037.515, and 1037.520. Where the test results will represent multiple vehicles or components with different emission performance, use good engineering judgment to select worst-case emission data vehicles or components. In the case of powertrain testing under §1037.550, select a test engine and test transmission by considering the whole range of vehicle models covered by the powertrain family and the mix of duty cycles specified in §1037.510.

(b) Test your emission-data vehicles (including emission-data components) using the procedures and equipment specified in subpart F of this part. Measure emissions (or other parameters, as applicable) using the specified procedures.

(c) We may perform confirmatory testing by measuring emissions (or other parameters, as applicable) from any of your emission-data vehicles.

(1) We may decide to do the testing at your plant or any other facility. If we do this, you must deliver the vehicle or component to a test facility we designate. The vehicle or component you provide must be in a configuration that is suitable for testing. For example, vehicles must have the tires you used for testing, and tractors must be set up with the trailer you used for testing. If we do the testing at your plant, you must schedule it as soon as possible and make available the instruments, personnel, and equipment we need (see paragraph (g) of this section for provisions that apply specifically for testing a tractor's aerodynamic performance).

(2) If we measure emissions (or other parameters, as applicable) from your vehicle or component, the results of that testing become the official emission results for the vehicle or component. Note that changing the official emission result does not necessarily require a change in the declared modeling input value. Unless we later invalidate these data, we may decide not to consider your data in determining if your vehicle family meets applicable requirements.

(3) Before we test one of your vehicles or components, we may set its adjustable parameters to any point within the physically adjustable ranges, if applicable.

(4) Before we test one of your vehicles or components, we may calibrate it within normal production tolerances for anything we do not consider an adjustable parameter. For example, this would apply for a vehicle parameter that is subject to production variability because it is adjustable during production, but is not considered an adjustable parameter (as defined in §1037.801) because it is permanently sealed. For parameters that relate to a level of performance that is itself subject to a specified range (such as maximum power output), we will generally perform any calibration under this paragraph (c)(4) in a way that keeps performance within the specified range. Note that this paragraph (c)(4) does not allow us to test your vehicles in a condition that would be unrepresentative of production vehicles.

(d) You may ask to use carryover data for a vehicle or component from a previous model year instead of doing new tests if the applicable emission-data vehicle from the previous model year remains the appropriate emission-data vehicle under paragraph (b) of this section.

(e) We may require you to test a second vehicle or component of the same configuration in addition to the vehicle or component tested under paragraph (a) of this section.

(f) If you use an alternate test procedure under 40 CFR 1065.10 and later testing shows that such testing does not produce results that are equivalent to the procedures specified in subpart F of this part, we may reject data you generated using the alternate procedure.

(g) We may perform testing to verify your aerodynamic drag area values using any method specified in subpart F of this part. The following additional provisions apply:

(1) We intend to use the same aerodynamic test facility you used, and if you provide any instruments you used, we intend to use those instruments to perform our testing.

(2) We may perform coastdown testing to verify your tractor drag area for any certified configuration. If you use an alternate method for determining aerodynamic drag area for tractors, we may perform testing to verify Falt-aero as specified in subpart F of this part.

(3) We may test trailers (and devices receiving preliminary approval) using the wind-tunnel method described in §1037.530. We may also test using an alternate method; however, we will determine how to appropriately correct or correlate those results to testing with the wind-tunnel method.

(h) You may ask us to use analytically derived GEM inputs for untested configurations as identified in subpart F of this part based on interpolation of all relevant measured values for related configurations, consistent with good engineering judgment. We may establish specific approval criteria base on prevailing industry practice. If we allow this, we may test any configurations. We may also require you to test any configurations as part of a selective enforcement audit.