1.1 本规范涵盖了配备火花点火式发动机的地面车辆用液体汽车燃料要求的制定。 1.2 本规范描述了在各种操作条件下使用的汽车燃料的各种特性。它根据燃料使用地的季节性气候变化，提供了汽车燃料的挥发性和耐水性的变化。5月1日至9月15日期间，除阿拉斯加、夏威夷和美国领土外，美国环境保护局（EPA）为每个地理区域规定了最大蒸汽压限值。 中讨论了抗爆指数随季节气候变化和海拔高度的变化 附录X1 本规范既不一定包括所有类型的符合汽车要求的燃料，也不一定排除在某些操作条件下或在某些设备中性能不令人满意的燃料。本规范各项特性的重要性如所示 附录X1 . 1.3 本规范中涵盖的火花点火式发动机燃料是汽油及其与含氧化合物（如醇类和醚类）的混合物，其中汽油是混合物中的主要体积成分。含氧化合物的浓度和类型在本说明书中没有特别限制。 燃料的成分受到经济、法律和技术考虑的限制，但其特性（包括挥发性）由本规范定义。在许多国家，具有管辖权的监管机构制定了法律法规，限制火花点火式发动机燃料中含氧化合物和某些其他化合物的浓度。在美国，含氧化合物的类型和浓度仅限于根据美国环境保护局（EPA）基本类似的规则批准的含氧化合物（见 X3.3.1 )、豁免和部分豁免，包括对车辆和设备使用的一些限制（见 X3.3.2 ). 关于燃料特性，包括挥发性，本规范的限制性可能比美国环保局的规则、法规和豁免更大或更小。 提到 附录X3 讨论有关燃料挥发性、铅和磷含量、硫含量、苯含量、沉积物控制添加剂认证以及燃料中含氧化合物使用的EPA规则。有关最新版本的规则和附加要求，请联系EPA。 1.4 本规范不涉及重新配制的火花点火式发动机燃料的排放特性。某些地区需要重新配方的火花点火式发动机燃料来降低汽车的排放，其特性在关于重新配方的点火发动机燃料的专著12（MONO12）中进行了描述。 2. 然而，除了MONO12中的法律要求外，重新制定的火花- 点火发动机燃油应满足本规范中的性能要求。 1.5 本规范是自发布之日起对汽车燃料的描述。该规范正在不断审查中，可能会根据燃料、汽车要求或测试方法的变化或其组合进行修订。因此，本规范的所有用户应参考最新版本。 注1: 如果对最新版规范有任何疑问 D4814 ，联系ASTM国际总部。 1.6 必须首先确定所考虑的燃料类型，以便选择适用的测试。试验方法 D4815 提供了用于确定以质量百分比计的含氧化合物浓度的程序。 试验方法 D4815 还包括计算质量氧含量和含氧化合物浓度（体积百分比）的程序。 附录X4 提供了一种使用测得的含氧物类型、以体积百分比计的含氧物质浓度和测得的燃料密度或相对密度来计算燃料的质量氧含量的程序。 1.7 以下适用于本标准中的所有规定限值:为了确定是否符合这些规范，观察值或计算值应根据实践中的四舍五入方法，在表示规范限值时使用的最右边的有效数字中“四舍五舍五入到最接近的单位” E29 。对于用整数表示的规范限制，只有指定了小数点，尾随零才有效。对于以整数表示的指定限制，并且最右边的数字为非零，则最右边的位数是有效的，而不指定小数点。此约定适用于表1、表3和表X8.1中的规定限值，在本规范的其余部分中不会遵守此约定。 1.8 以国际单位制表示的数值为标准，除非美国联邦法规规定了其他单位。括号中给出的值仅供参考。 注2: 中显示的许多值 表1 最初是使用U开发的。 S.习惯单位，随后被软转换为SI值。因此，由于四舍五入，国际单位制数值的转换有时会与所示的美国习惯数值略有不同。在某些情况下，美国联邦法规规定了非国际单位制单位。 1.9 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.10 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。

1.1 This specification covers the establishment of requirements of liquid automotive fuels for ground vehicles equipped with spark-ignition engines. 1.2 This specification describes various characteristics of automotive fuels for use over a wide range of operating conditions. It provides for a variation of the volatility and water tolerance of automotive fuel in accordance with seasonal climatic changes at the locality where the fuel is used. For the period May 1 through September 15, the maximum vapor pressure limits issued by the United States (U.S.) Environmental Protection Agency (EPA) are specified for each geographical area except Alaska, Hawaii, and the U.S. Territories. Variation of the antiknock index with seasonal climatic changes and altitude is discussed in Appendix X1 . This specification neither necessarily includes all types of fuels that are satisfactory for automotive vehicles, nor necessarily excludes fuels that can perform unsatisfactorily under certain operating conditions or in certain equipment. The significance of each of the properties of this specification is shown in Appendix X1 . 1.3 The spark-ignition engine fuels covered in this specification are gasoline and its blends with oxygenates, such as alcohols and ethers and where gasoline is the primary component by volume in the blend. The concentrations and types of oxygenates are not specifically limited in this specification. The composition of fuel is limited by economic, legal, and technical consideration, but its properties, including volatility, are defined by this specification. In many countries, regulatory authorities having jurisdiction have set laws and regulations that limit the concentration of oxygenates and certain other compounds found in spark-ignition engine fuel. In the United States, oxygenate types and concentrations are limited to those approved under the U.S. Environmental Protection Agency's (EPA) substantially similar rule (see X3.3.1 ), waivers, and partial waivers including some restrictions on vehicle and equipment use (see X3.3.2 ). With regard to fuel properties, including volatility, this specification can be more or less restrictive than the EPA rules, regulations, and waivers. Refer to Appendix X3 for discussions of EPA rules relating to fuel volatility, lead and phosphorous contents, sulfur content, benzene content, deposit control additive certification, and use of oxygenates in the fuel. Contact the EPA for the latest versions of the rules and additional requirements. 1.4 This specification does not address the emission characteristics of reformulated spark-ignition engine fuel. Reformulated spark-ignition engine fuel is required in some areas to lower emissions from automotive vehicles, and its characteristics are described in Monograph 12 (MONO12) on reformulated spark-ignition engine fuel. 2 However, in addition to the legal requirements found in MONO12, reformulated spark-ignition engine fuel should meet the performance requirements found in this specification. 1.5 This specification represents a description of automotive fuel as of the date of publication. The specification is under continuous review, which can result in revisions based on changes in fuel, automotive requirements, or test methods, or a combination thereof. All users of this specification, therefore, should refer to the latest edition. Note 1: If there is any doubt as to the latest edition of Specification D4814 , contact ASTM International Headquarters. 1.6 The type of fuel under consideration must first be identified in order to select applicable tests. Test Method D4815 provides a procedure for determining oxygenate concentration in mass percent. Test Method D4815 also includes procedures for calculating mass oxygen content and oxygenate concentration in volume percent. Appendix X4 provides a procedure for calculating the mass oxygen content of a fuel using measured oxygenate type, oxygenate concentration in volume percent, and measured density or relative density of the fuel. 1.7 The following applies to all specified limits in this standard: For purposes of determining conformance with these specifications, an observed value or a calculated value shall be rounded “to the nearest unit” in the right-most significant digit used in expressing the specification limit, in accordance with the rounding method of Practice E29 . For a specification limit expressed as an integer, a trailing zero is significant only if the decimal point is specified. For a specified limit expressed as an integer, and the right-most digit is non-zero, the right-most digit is significant without a decimal point being specified. This convention applies to specified limits in Tables 1, 3, and X8.1, and it will not be observed in the remainder of this specification. 1.8 The values stated in SI units are the standard, except when other units are specified by U.S. federal regulation. Values given in parentheses are provided for information only. Note 2: Many of the values shown in Table 1 were originally developed using U.S. customary units and were subsequently soft-converted to SI values. As a result, conversion of the SI values will sometimes differ slightly from the U.S. customary values shown because of round-off. In some cases, U.S. federal regulations specify non-SI units. 1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.10 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.