Engine Coolant & Antifreeze vs. ILSAC Standards
Comparing 2 standards across 12 specifications. 12 key differences identified.
Automotive Engine Coolant (standardized under ASTM D3306 and SAE J1034) consists of an ethylene glycol (or propylene glycol) base mixed 50/50 with demineralized water and specialized corrosion inhibitor additive packages. Dividing into classical IAT (Inorganic Acid), modern OAT (Organic Acid Technology / Long Life), and HOAT (Hybrid OAT with silicates/phosphates).
ILSAC GF-6 (developed by the International Lubricant Standardization and Approval Committee of Japanese and American automakers) defines fuel economy, timing chain wear reduction, and engine durability standards. Splitting into GF-6A (backward-compatible for 0W-20, 5W-20, 5W-30, 10W-30) and GF-6B (dedicated to ultra-low viscosity 0W-16 oils).
Specification Comparison Table
12 Parameters| Parameter / Spec | ||
|---|---|---|
|
Base Liquid Mixture
|
50/50 mix of Ethylene Glycol and pure demineralized water (Freeze point: -37°C / -34°F; Boil point: 108°C / 226°F at 1 atm, 129°C / 265°F under 15 psi cap) | — |
|
IAT (Inorganic Acid Technology — Green)
|
Silicate and phosphate inhibitors (2-year / 30,000-mile service life; standard on pre-2000 vehicles with cast-iron blocks and copper radiators) | — |
|
OAT (Organic Acid Technology — Orange/Pink)
|
Carboxylate-based inhibitors (5-year / 150,000-mile long-life; GM Dex-Cool, VW G12/G12+, Toyota Super Long Life, Ford Orange) | — |
|
Si-OAT / HOAT (Hybrid OAT — Violet/Blue/Yellow)
|
Combines organic acids with low-depletion silicates or phosphates (VW G13/G12evo, Mercedes MB 325.5, BMW Blue/Magenta, Asian P-HOAT) | — |
|
Asian P-HOAT (Phosphated HOAT — Pink/Blue)
|
Uses phosphates instead of silicates (Toyota, Honda, Nissan, Subaru, Hyundai/Kia strictly forbid silicates due to water pump seal erosion) | — |
|
European Si-HOAT (Silicated HOAT)
|
Uses silicates instead of phosphates (European water has high calcium hardness; phosphates create calcium phosphate scale deposits) | — |
|
Standardization
|
— | ILSAC GF-6A / ILSAC GF-6B (Mandated May 2020) |
|
ILSAC GF-6A (Starburst Symbol)
|
— | Backward compatible with older GF-5 and GF-4 specifications for SAE 0W-20, 5W-20, 0W-30, 5W-30, 10W-30 |
|
ILSAC GF-6B (Shield Symbol)
|
— | Exclusively for SAE 0W-16 viscosity oils (NOT backward compatible with engines requiring GF-6A / GF-5) |
|
Timing Chain Wear Test (Sequence X)
|
— | A mandatory ASTM test that limits acceptable timing chain elongation over an extended multi-day cyclic engine run (specific pass/fail thresholds are set by the ASTM Sequence X test procedure, not reproduced here in full) |
|
Piston Deposit & Cleanliness (Sequence IIIH)
|
— | A high-temperature ASTM oxidation/deposit test that runs the oil under sustained elevated temperature to evaluate resistance to ring sticking and varnish formation (exact duration/temperature are set by the ASTM Sequence IIIH test procedure) |
|
Automaker Backing
|
— | Alliance of Automobile Manufacturers (Ford, GM, Stellantis) and Japan Automobile Manufacturers Association (Toyota, Honda, Nissan) |