I am trying to decide between Dexcool and regular coolant. I came across this commentary, which was written by a well respected guy in the Street Rod world. Please read and discuss.
There has been a controversial discussion going on about "Red" or Dexcool antifreeze and regular "Green" antifreeze at many car sites and garages. Many believe that the Dexcool supplied in cars today plug and corrode more than they protect. I have seen scaling with my own two eyes in Dexcool engines and only run ethlene glycol (EG) or the green stuff in my cars at this point. Read on...it's my usual science lesson dribble.
First, one myth is that all red antifreezes are Dexcool. This is not the case. There are standard EG antifreezes that are red and cars that have Dexcool will be labeled as such. Both ethylene glycol (EG) and propylene glycol (PG) are used as the antifreeze base. Additional additives and inhibitors are added to packages depending on manufacturer. Each glycol has supporters and pundits, although the best choice depends on the intended use. There are several considerations to be made when choosing an antifreeze, the most important being performance. Notwithstanding the heat carrying abilities of both, additives determine most performance criteria so all coolants supplied by a respectable manufacturer will perform well.
The one major difference in EG and PG is toxicity. In antifreeze we are most concerned about accidental ingestion by pets and children. The acute toxicity of PG is substantially lower than that of EG. Propylene glycol, like alcohol, is not toxic at low levels (we all know what happens there tho....whooooooah).
Another controversial issue is phosphate additive use in EG based brands. In many US and Japanese antifreeze formulas phosphate is added as a corrosion inhibitor. European vehicle manufacturers recommend against the use of phosphate containing antifreeze. In the US market, a phosphate inhibitor is included in many formulas to provide several important functions that help reduce automotive cooling system damage. The benefits provided by the phosphate include:
-Protect aluminum engine components by reducing cavitation corrosion during high speed driving.
-Provide for corrosion protection to ferrous metals.
-Act as a buffer to keep the antifreeze mixture alkaline. (This prevents acid build-up that will damage or destroy metal engine parts)
European manufacturers feel that these benefits are achievable with inhibitors other than phosphate. Their main concerns with phosphate containing products are the potential for solids dropout when mixed with hard water. Solids can collect on cooling system walls forming what is known as scale. This concern comes from the fact that European water is much harder than water in the US. Because phosphate "softens" water by forming solids of calcium or magnesium salts that can dropout of solution, there is potential for cooling system blockage. The phosphate level in most US and Japanese antifreeze formulas do not generate significant solids.
The concern with mixing the two comes from the fact that there are very different chemical inhibitor packages in use than Dexcool. Most leading technologies will work very well when used as intended, typically at 50% or less in good quality and preferably distilled water. Actually, most tap water will do without doing any damage as well. If the EG becomes mixed with Dexcool, however, one study showed a possible aluminum corrosion problem in certain situations. The other question is a concern for dilution of the protection packages due to cross contamination.
I personally would not recommend Dexcool in a vehicle that did not come from the factory with Dexcool in the cooling system. It would be very difficult, if not impossible, to flush out all the conventional anti-freeze coolant from the cooling system of an older vehicle, and any conventional anti-freeze would contaminate the Dexcool. This is not good.
Compared to old-fashioned phosphated antifreeze, Dexcool may be more stable and slighty improve water pump life, even though most water pumps today do not need lubrication. Evaluations of the two technologies to compare their respective service lives have found them comparable by both GM and Ford. No gain there.
After all the long drawn out speech, my conclusion is this, if your car came from the factory with Dexcool, use Dexcool for replacement or to top off. If your car came from the factory with standard "green" antifreeze, use that for replacement or to toping off. Case in point also. Dexcool has been known to cause failure of head gaskets in certain applications also. I just had to throw that in.
For me and mine......simply green will do!
I report.....you decide?
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Steve Jack
Engineering & Marketing Technologies
ConceptOne Brackets and Pulleys
