The Ultimate Guide to Glycol Base Engine Coolant for Cars and Light Duty Service
Scope
The scope of this specification pertains to engine coolants used in light-duty service cooling systems, specifically those containing ethylene glycol, propylene glycol, or ethylene glycol with glycerin. These coolants, when used as concentrates at 40% to 60% concentration (with allowance up to 70% with agreement between manufacturer and user) in water, or as pre-diluted (concentrate) glycol base engine coolants at 50 volume % or higher, will effectively protect against freezing, boiling, and corrosion.
The coolants governed by this specification are categorized as follows:
| Coolant Type | Description |
|---|---|
| I | Ethylene glycol base concentrate |
| II | Propylene glycol base concentrate |
| III | Ethylene glycol predilute 50% volume or higher engine coolant concentrate |
| IV | Propylene glycol predilute 50% volume or higher engine coolant concentrate |
| V | Ethylene glycol base concentrate containing glycerin |
| VI | Ethylene glycol base predilute containing glycerin 50 volume % or higher engine coolant concentrate |
ASTM D3306-21 is a specification that outlines the performance requirements for engine coolants made from new or virgin ingredients. It also applies to engine coolants made from recycled or reprocessed used coolant or industrial-source glycol, as long as they meet the requirements of Specification E1177. However, separate specifications (D6471 and D6472) exist for engine coolants made from recycled or reprocessed used coolant or industrial-source glycol that do not meet the requirements of Specification E1177. Additionally, this specification applies to glycol-based engine coolants made using fully refined glycerin, provided that the glycerin meets the requirements outlined in Specification D7640.
ASTM D3306-21 specifies that the standard units of measurement are in the International System of Units (SI). Any values given in parentheses after the SI units are provided for informational purposes only and are not considered standard.
The ASTM D3306-21 standard acknowledges that it may not cover all safety concerns related to its use. Therefore, it is up to the user of this standard to ensure that appropriate safety, health, and environmental practices are established and that regulatory limitations are considered before using it.
ASTM D3306-21 is a specification that pertains to engine coolant for automobiles and light-duty service. It specifically applies to glycol-based coolants. However, for heavy-duty engine service, there are separate specifications, namely D4985 and D6210.
ASTM D3306-21 is an international standard that was created following established principles of standardization recognized worldwide. These principles were established by the World Trade Organization Technical Barriers to Trade (TBT) Committee in their Decision on Principles for the Development of International Standards, Guides, and Recommendations. The purpose of this standard is to provide a consistent and reliable method for testing the performance of engine coolants.
