2019 NAPA Reference Guide

Information About Antifreeze (Glycol) Ethylene (EG) & Propylene (PG) Traditional: Inorganic Acid Technology (IAT) Automotive Automotive/Conventional Traditional coolant formulated to provide protection for automotive gasoline engines. Mixture includes high levels of silicates to protect aluminum parts in automotive engines. May also contain phosphates. Not suitable for use in heavy medium duty diesel engines. No SCA used with this type of coolant. Heavy Duty Standard Service Interval (S.S.I) No to very low levels of silicates. Not suitable for use in automotive gasoline engines. Must use SCAs. Often labeled as a Fleet or Heavy Duty coolant. Intended to provide corrosion protection only when used and maintained with SCAs. Requires Pre-Charge of SCAs to establish proper inhibitor levels, followed by lower doses of SCAs in a Maintenance amount. SCAs are available in both liquid and dry form. Manufacturer’s recommendations for Pre- Charge and Maintenance doses and intervals must be followed. Requires SCA testing. Pre-Charged Standard Service Interval (S.S.I) Traditional HD coolant with low to no levels of silicates premixed with a Pre-Charge level of SCAs and deionized quality water. No additional charge of SCAs should be used on Initial installation. Does require Maintenance dose of SCAs thereafter. Requires SCA testing. Slow Release Service Interval (S.R.I.) Specially formulated SCA package that releases over time. Used with traditional low/no silicate coolant to extend the maintenance service intervals. Requires SCA testing. Extended Service Interval (E.S.I.) Specially formulated SCA package that requires less maintenance over time. Used with low/no silicate coolant to extend the maintenance service intervals. Requires SCA monitoring and maintenance. Extended/Long Life: Organic Acid Technology (OAT) Automotive Organic Acid Technology OAT Formulated with ethyl hexanoic acid as its chief organic inhibitor. It does not use any traditional buffers thus it is commonly called a full OAT coolant. i.e. Dexcool. No additional SCAs used with this coolant. Hybrid Organic Acid Technology HOAT Formulated with both organic inhibitors plus strong buffer compounds. Often uses borates one of the buffer compounds. As a mixture with traditional buffers and OAT inhibitors, this coolant is called a Hybrid thus the acronym HOAT. i.e. G-05 Gold Some HOAT coolants also incorporate nitrite buffer compounds and are recommended by their manufacturer for use in light duty to medium duty diesel engines. No additional SCAs used with this coolant. Partial Organic Acid Technology POAT Organic Acid based coolant forumulated for use in automotive engines with high levels of aluminum parts. Developed to be more compatible with seal and system components. Not suitable for use in medium or heavy duty diesel engines. No additional SCAs used with this coolant. Often premixed with deionized water. Heavy Duty Nitrited Organic Acid Technology NOAT Organic Acid based glycol coolant formulated with traditional buffers and corrosion inhibitors. Nitrite is a key corrosion inhibitor/buffer. Requires organic acid booster at the half way point of its recommended service interval. No additional SCAs, either liquid or dry, are to be used with this coolant. No SCA testing. Partial Organic Acid Technology POAT Organic Acid based glycol coolant formulated with additional buffers and corrosion inhibitors. No additional SCAs, either liquid or dry, are to be used with this coolant. No SCA testing. Nitrite, Amine, Phosphate, Silicate Free NAPS Organic Acid based glycol coolant formulated with additional buffers and corrosion inhibitors. No additional SCAs, either liquid or dry, are to be used with this coolant. No SCA testing. 1057