BTW, for those suggesting "just buy the honda antifreeze", doing it myself, it would cost $10/car with prestone and $40/car with honda antifreeze. I'd rather not give my money to those bastards if I don't have to.
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Subject: Honda Anti-Freeze
Recently, several people have questioned whether the coolant (anti-freeze) sold by Honda and Acura dealers is different from the popular mass-market brands.
Honda has sent the information attached below to its dealers. While you might not expect the source to be exactly unbiased, it does provide technical information and justification for differences in their formula.
Genuine Honda Coolant is the Only Way to Go -------------------------------------------
Increasingly severe operating conditions and the advent of lower maintenance requirements have resulted in significant changes in the variety and the concentration of additives used in engine coolant. Also, the continual improvements in engine and vehicle design have challenged coolant suppliers to design products that perform well in a more demanding environment.
To meet these needs, Honda engineers have developed a superior, high-quality coolant that has several advantages over the competition.
Some antifreeze, although labeled as safe for aluminum parts, may not be compatible with Acura cooling system components. Extensive research and testing by both Honda R&D and CCI, the manufacturer of the Honda coolant, have proven that the abrasive silicates and/or borates found in most domestic coolants can cause these problems:
- Silicates bond to the surface of the water pump seal and act as an abrasive, causing considerable seal erosion and coolant leakage. In actual tests, the silicated coolant caused early leakage. This leakage increased dramatically until a substantial portion of the coolant had been lost. In contrast, the Honda coolant had almost no leakage through the duration of the test.
Chart here, entitled "Coolant Leakage from Water Pump Seal", showing Leaked Coolant Volume in ml as follows for each test duration in Hours:
24 hrs: Honda Coolant 0, Typical Silicated Coolant 21 48 hrs: Honda Coolant 1, Typical Silicated Coolant 36 72 hrs: Honda Coolant 2, Typical Silicated Coolant 47 96 hrs: Honda Coolant 2, Typical Silicated Coolant 55 120 hrs: Honda Coolant 2.5, Typical Silicated Coolant 56 144 hrs: Honda Coolant 3.5, Typical Silicated Coolant 57 168 hrs: Honda Coolant 4, Typical Silicated Coolant 58.8 192 hrs: Honda Coolant 6, Typical Silicated Coolant 63 200 hrs: Honda Coolant 6, Typical Silicated Coolant 64
- Silicates tend to gel and settle in the coolest parts of the cooling system, causing radiator plugging and overheating.
- Borates cause pitting corrosion on the cylinder head.
- Silicate inhibitors are difficult to stabilize and, therefore, limit coolant shelf life.
Most commercially available coolants were originally designed for cast iron engines. Silicate, an inexpensive additive, was added to coolants to prevent aluminum corrosion, but the long-term durability of the combination was not tested.
In contrast, Honda coolant was designed specifically for aluminum engines. It contains an organic corrosion inhibitor instead of silicate. This superior formula gives these advantages:
- No silicate abrasion of water pump seals. For example, these graphs show the surface roughness of two aluminum water pump seal rings. Seal A, exposed to silicated coolant, shows considerable damage. Seal B, exposed to Honda coolant, displays only minute wear.
(graphs here, showing roughness across the surface, with A a very wiggly line, and B a very smooth line)
- No plugging or overheating caused by silicate gelling.
- Excellent corrosion protection for aluminum components.
- Long-term corrosion protection for other cooling system materials (steel, cast iron, copper, solder, gaskets, seals, and O-rings).
