40 CFR § 1065.710 - Gasoline.
(a) This section specifies test fuel properties for gasoline with ethanol (low-level blend only) and for gasoline without ethanol. Note that the “fuel type” for the fuels specified in paragraphs (b) and (c) of this section is considered to be gasoline. In contrast, fuels with higher ethanol concentrations, such as fuel containing 82 percent ethanol, are considered to be ethanol fuels rather than gasoline. We specify some test fuel parameters that apply uniquely for low-temperature testing and for testing at altitudes above 1,219 m. For all other testing, use the test fuel parameters specified for general testing. Unless the standard-setting part specifies otherwise, use the fuel specified in paragraph (c) of this section for general testing.
(b) The following specifications apply for a blended gasoline test fuel that has nominally 10% ethanol (commonly called E10 test fuel):
(1) Prepare the blended test fuel from typical refinery gasoline blending components. You may not use pure compounds, except as follows:
(i) You may use neat ethanol as a blendstock.
(ii) You may adjust the test fuel's vapor pressure by adding butane.
(iii) You may adjust the test fuel's benzene content by adding benzene.
(iv) You may adjust the test fuel's sulfur content by adding sulfur compounds that are representative of those found with in-use fuels.
(2) Table 1 of this section identifies limit values consistent with the units in the reference procedure for each fuel property. These values are generally specified in international units. Values presented in parentheses are for information only. Table 1 follows:
Table 1 of § 1065.710 - Test Fuel Specifications for a Low-Level Ethanol-Gasoline Blend
|General testing||Low-temperature testing||High altitude testing|
|Antiknock Index (R + M)/2||87.0 - 88.4 2||87.0 Minimum||ASTM D2699 and D2700.|
|Sensitivity (R-M)||7.5 Minimum||ASTM D2699 and D2700.|
|Dry Vapor Pressure Equivalent (
|°C ( °F)||49-60
|50% evaporated||°C ( °F)||88-99 (190-210).|
|90% evaporated||°C ( °F)||157-168 (315-335).|
|Evaporated final boiling point||°C ( °F)||193-216 (380-420).|
|Total Aromatic Hydrocarbons||volume %||21.0-25.0||ASTM D5769.|
|C6 Aromatics (benzene)||volume %||0.5-0.7.|
|C7 Aromatics (toluene)||volume %||5.2-6.4.|
|C8 Aromatics||volume %||5.2-6.4.|
|C9 Aromatics||volume %||5.2-6.4.|
|C10 + Aromatics||volume %||4.4-5.6.|
|Olefins 5||mass %||4.0-10.0||ASTM D6550.|
|Ethanol blended||volume %||9.6-10.0||See paragraph (b)(3) of this section.|
|Ethanol confirmatory 6||volume %||9.4-10.2||ASTM D4815 or D5599.|
|Total Content of Oxygenates Other than Ethanol 6||volume %||0.1 Maximum||ASTM D4815 or D5599.|
|Sulfur||mg/kg||8.0-11.0||ASTM D2622, D5453 or D7039.|
|Lead||g/liter||0.0026 Maximum||ASTM D3237.|
|Phosphorus||g/liter||0.0013 Maximum||ASTM D3231.|
|Copper Corrosion||No. 1 Maximum||ASTM D130.|
|Solvent-Washed Gum Content||mg/100 milliliter||3.0 Maximum||ASTM D381.|
|Oxidation Stability||minute||1000 Minimum||ASTM D525.|
2 Octane specifications apply only for testing related to exhaust emissions. For engines or vehicles that require the use of premium fuel, as described in paragraph (d) of this section, the adjusted specification for antiknock index is a minimum value of 91.0; no maximum value applies. All other specifications apply for this high-octane fuel.
3 Calculate dry vapor pressure equivalent, DVPE, based on the measured total vapor pressure, pT, using the following equation: DVPE (kPa) = 0.956 · pT - 2.39 or DVPE (psi) = 0.956 · pT - 0.347. DVPE is intended to be equivalent to Reid Vapor Pressure using a different test method.
4 Parenthetical values are shown for informational purposes only.
5 The reference procedure prescribes measurement of olefin concentration in mass %. Multiply this result by 0.857 and round to the first decimal place to determine the olefin concentration in volume %.
6 ASTM D5599 prescribes concentration measurements for ethanol and other oxygenates in mass %. Convert results to volume % as specified in Section 14.3 of ASTM D4815.
(3) The ethanol-blended specification in Table 1 of this section is based on the volume % ethanol content of the fuel as determined during blending by the fuel supplier and as stated by the supplier at the time of fuel delivery. Use good engineering judgment to determine the volume % of ethanol based on the volume of each blendstock. We recommend using a flow-based or gravimetric procedure that has an accuracy and repeatability of ±0.1%.
(c) The specifications of this paragraph (c) apply for testing with neat gasoline. This is sometimes called indolene or E0 test fuel. Gasoline for testing must have octane values that represent commercially available fuels for the appropriate application. Test fuel specifications apply as follows:
Table 2 of § 1065.710 - Test Fuel Specifications for Neat (E0) Gasoline
|Property||Unit||Specification||Reference procedure 1|
|Evaporated initial boiling point||°C||24-35 2||24-36||ASTM D86|
|Evaporated final boiling point||Maximum, 213||Maximum, 212|
|Olefins||volume %||Maximum, 10||Maximum, 17.5||ASTM D1319|
|Aromatics||Maximum, 35||Maximum, 30.4|
|Lead||g/liter||Maximum, 0.013||Maximum, 0.013||ASTM D3237|
|Phosphorous||g/liter||Maximum, 0.0013||Maximum, 0.005||ASTM D3231|
|Total sulfur||mg/kg||Maximum, 80||Maximum, 80||ASTM D2622|
|Dry vapor pressure equivalent 3||kPa (psi)||60.0-63.4 2 4 (8.7-9.2)||77.2-81.4 (11.2-11.8)||ASTM D5191|
2 For testing at altitudes above 1219 m, the specified initial boiling point range is (23.9 to 40.6) °C and the specified volatility range is (52.0 to 55.2) kPa ((7.5 to 8.0) psi).
3 Calculate dry vapor pressure equivalent, DVPE, based on the measured total vapor pressure, pT, in kPa using the following equation: DVPE (kPa) = 0.956 · pT−2.39 or DVPE (psi) = 0.956 · pT−0.347. DVPE is intended to be equivalent to Reid Vapor Pressure using a different test method.
4 For testing unrelated to evaporative emissions, the specified range is (55.2 to 63.4) kPa ((8.0 to 9.2) psi).