This comes from a old Acura Service News Article. I have seen more than a few premature waterpump failures on Acura vehicles that had been using aftermarket coolant.
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.
Coolant Leakage From Water Pump Seal
• 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.
Seal A – Silicated Coolant
Seal B – Honda Coolant
• 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).
You can find less expensive coolants on the
market, but now you can see why genuine Honda
coolant is the only coolant approved for Acura
vehicles (it must be used for warranty repairs).
Honda’s non-silicate formula delivers added
protection not offered by 95 percent of other brands.
Since our customers expect lower maintenance,
you’re doing them an injustice if you use any other
coolant.
