Antifreeze

Its interesting how there are now so many different kinds of antifreeze, and the worst part is the lack of knowledge of these different kinds. The key is to stay with what your manufacturer recommends, or do a complete chemical flush if you want to change, and then watch your seals big time just in case. I really wonder about the quick lube places where who knows what type of coolant you are getting.

Here are the 5 types
1. Ethylene Glycol Traditional green, but it has silicates which can be deadly to the seals used in Japanese cars.

2. Ethylene Glycol Low low or no silicate formulation, uses phosphates instead of silicates. Typically known as Toyota Red.

3. Propylene Glycol – This uses silicates, but its main attribute is lower toxicity. In fact, it is used in fog machines, and some softdrinks. I’m not toally convinced of its use as a coolant, but the low toxicity is important if you have pets running around.

4. Organic Acid Technology (OAT) Dexcool Recyclable and biodegradable antifreeze which is based on organic acids and is silicate- and phosphate-free. This however is not exactly clear cut. There are lots of stories as to this being very damaging. There was a lawsuit filed sometime back. It may or may not be a good idea. Certainly mixing it with other antifreeze is a really bad idea, or using it in cars not designed for it will probably kill them. Wharever you do, don’t top off with Ethylene glycol.

5. Ethylene Glycol-based ‘Hybrid Organic Acid Technology’ (HOAT). Uses Ethylene Glycol, but with OAT-based corrosion inhibitors and some added silicates; most usually BASF’s “Glysantin” additive package is used (also known as ‘G-05′). HOAT is less agressive than straight OAT anti-freeze and has better cavitation resistance. Same deal, don’t mix it, and who knows about the long term effects.

Now the key is changing antifreeze and flushing the system periodically. Personally, I think the 5 year span is way too long, but we shall see what happens. The longer you wait, the more concentrated hazmat you pick up in the coolant too, which is another reason to do so every couple years, or even every year.

Next key thing is not to use tap water. Most contain a significant number of minerals and contaminants, which can cause corrosion in the radiator. Now, the anticorrosion additives are supposed to help, but why take a chance. Distilled water, or even reverse osmosis water is a lot safer.

Next is the concentration. 50/50 is a minimum. If you go lower than that due to high local temperatures, you can cut yourself short on the corrosion inhibitors, and incude early failure, especially if you use tap water. In my location, I run 70/30, as we encounter temperatures below -25 deg F, and the coldest I’ve ever experienced was -37 deg F, although an engine preheater is mandatory at those temperatures.

Yet another reason for changing fluid is evaporation through the hoses of the cooling system. It can and does happen. Gates has a really cool calculator for determining loss through the hoses. Sure, they want to sell you there hose, but it does make a lot of sense.