§ 1051.245 How do I demonstrate that my engine family complies with evaporative emission standards?

(a) For purposes of certification, your engine family is considered in compliance with the evaporative emission standards in subpart B of this part if you do either of the following: (1) You have test results showing permeation emission levels from the fuel tanks and fuel lines in the family are at or below the standards in § 1051.110 throughout the useful life. (2) You comply with the design specifications in paragraph (e) of this section. (b) Your engine family is deemed not to comply if any fuel tank or fuel line representing that family has test results showing a deteriorated emission level above the standard. (c) To compare emission levels with the emission standards, apply deterioration factors to the measured emission levels. For permeation emissions, use the following procedures to establish an additive deterioration factor, as described in § 1051.240(c)(2): (1) Section 1051.515 specifies how to test your fuel tanks to develop deterioration factors. Small-volume manufacturers may use assigned deterioration factors that we establish. Apply the deterioration factors as follows: (i) Calculate the deterioration factor from emission tests performed before and after the durability tests as described in § 1051.515(c) and (d), using good engineering judgment. The durability tests described in § 1051.515(d) represent the minimum requirements for determining a deterioration factor. You may not use a deterioration factor that is less than the difference between evaporative emissions before and after the durability tests as described in § 1051.515(c) and (d). (ii) Do not apply the deterioration factor to test results for tanks that have already undergone these durability tests. (2) Determine the deterioration factor for fuel lines using good engineering judgment. (d) Collect emission data using measurements to one more decimal place than the applicable standard. Apply the deterioration factor to the official emission result, as described in paragraph (c) of this section, then round the adjusted figure to the same number of decimal places as the emission standard. Compare the rounded emission levels to the emission standard for each emission-data vehicle. (e) You may demonstrate for certification that your engine family complies with the evaporative emission standards by demonstrating that you use the following control technologies: (1) For certification to the standards specified in § 1051.110(a) with the control technologies shown in the following table: Table 1 of § 1051.245—Design-certification Technologies for Controlling Tank Permeation (2) For certification to the standards specified in § 1051.110(b) with the control technologies shown in the following table: Table 2 of § 1051.245—Design-certification Technologies for Controlling Fuel-line Permeation