Some ruminations on antifreeze (2025 Update)

Dood, I don't know where you're "coming from", but you are screwing up. Peak is selling BS to sell you their antifreeze. Worse than the phosphate issue is the silicate issue. Notice they don't say much about silicates on the Peak site. European cars need low silicate as well as low phosphate. It's incredible that you buy that "low mineral content in the USA vs. Europe" crap from Peak. Water is different all across the USA, as it is in Europe.

You can get a quality, low silicate, low phosphate coolant from Valvoline for about $9/gallon. Why screw around challenging what the engineers who built your car recommended when you can do it right for $5/year ?

? Silicon dioxide can be used as an abrasive, but a silicate is not silicon dioxide, nor is it a silicone, which is also not abrasive as your girlfriend may or may not be able to demonstrate to your satisfaction. As for silicate being "an abrasive" check out ordinary old sodium silicate... a liquid.

Sodium silicate was exactly what most antifreeze compounders used in their formulations. It was there to protect aluminum parts, supposedly.

It caused a lot of precipitation problems. Silicate precipitates because it forms insoluble salts with a number of things, like magnesium, etc. It also 'dehydrates' to form silica solids.

Phosphate is really not so bad to use in these formulations. It does things to stop certain types of iron corrosion that are not easily done otherwise. The phoshate precipitation is much less of a problem and is easier to handle than the silicate.

As an aside, silicone greases are often just silicone oils formulated with fumed silica. So, as you say, the broad indictment of silica or silicates as being abrasive is not necessarily justified.

Havoline?

Have you used it in Hondas?

On the Honda newsgroups it seems to me a clear majority indicate the OEM anti-freeze is the only option for them, based on a lot of experience (with early Honda water pump bearing failures IIRC) and not just Honda salespeople.

I suspect Prestone led to at least one early fairlure of one water pump on my

I am now experimenting with the Havoline Dex stuff. I am also increasing the frequency of my radiator coolant flushes. Yet I would not advise Honda owners who don't have the time and who don't want want the trouble to do this.

To play it safe, buy the Honda OEM anti-freeze for your Honda.

I imagine they're fine for some car makes but not others.

My Corolla book does specify silicate and phosphate free coolant. The engine block, head, water pump, and radiator are aluminum. Last week I performed the first coolant change and bought the genuine Toyota coolant. Price was $12.95 for a gallon (a wee bit more than required). Prestone 5 yr ("orange") was $9.00. Prestone regular ("green") a couple bucks less. A few bucks for the right stuff .... spread over the next 50k miles is nothing. Nothing.

Damn Larry, you much be a chemist in the antifreeze field.

How true. All we can do is rely on observation and our experiences, and use a little intelligent reasoning.

Never a more accurate statement than this! Of course, corporate America just LOVES the hordes who buy into their sales hype.

-- Cliff

Amen. To read some of these owner's manuals, you'd swear that Honda or Toyota aluminum atoms follow completely different laws of physics and chemistry than Ford or Chrysler aluminum atoms.

Use the over-priced factory spooge through the warranty, then use a proven formula afterward. And don't use Dex-Cool in ANYTHING except a GM that calls for it and also has a good warranty in place.... and keep your fingers crossed too :-)

"Cliff Freeling" wrote

snip

I agree and have similar experience. (I am an amateur home mechanic for very basic car maintenance, like pretty much everything listed in the car's suggested maintenance schedule.) I too loathe unnecessarily enriching corporate America. E.g. I sure as heck don't change my oil every 3000 miles (anymore ;-) ). I'd rather give the savings to charity.

Yet I hope we agree sometimes one does get what one pays for. Using OEM anti-freeze might be one such instance, based on the many posts here on the subject that talk about specific problems people feel their Hondas have had when using NON-OEM anti-freeze, and the subsequent better performance when they switched to OEM. Some of the people I respect most (e.g. who don't bullshit, who don't push people around, and who admit their own mistakes over the years so as to help others) in the group have this view based on personal experience with their Hondas. I think I for one would be foolish to ignore it.

I appreciate your opinion. Barring further data, perhaps the Orange Dex is at least a middle ground between the green Prestone/Peak and the OEM stuff. I will keep the group posted... ;-)

A few bucks for the right stuff ....

I have to agree, Philip. There is little to be gained. For some of these companies, the earnings for 'new technology' can be enormous.

A delegation of us went to tour a packaging company recently where motor oil, antifreeze, etc are received, blended and packaged for the major suppliers. Names such as Valvoline, Shell, Peak, and a number of others were on the containers.

I will not say that all the products came out of the same blend vessel, but some certainly did. ; > )

You were doing Ok, until you started off on this tangent. There is nothing wrong with using Dexcool in a modern engine and its arguably a better antifreeze with a much longer-life additive package. You do want a very good flush beforehand as there is some evidence of problems with the organize acid chemistry in Dexcool reacting poorly with the additive package in conventional ethylene glycol AF.

- Mark

I believe such problems also occur all the time with conventional "green" AF's, the introduction of Dexcool just was a convenient whipping boy for the types of cooling system problems that occur in cars all thetime. But neither of us have hard data, so not worth taking further.

- Mark

You realize that Dexcool is almost all EG also, don't you? The only difference between conventional EG and Dexcool is an organic acid corrosion inhibitor package instead of the typical phosphate, silicate corrosion inhibitor package. I don't see any mechanism where a slightly different corrosion inhibitor package could take 8-qts of coolant and turn it into mud.

Just like oil, AF's are a huge source or urban legend mythology.

- Mark

Yup.

I see no reason that changing the additive package couldn't have a huge effect on how the coolant behaves in a closed system. I've seen pictures of the insides of engines (GM engines for which the crap was recommended and nothing else ever used) filled with the muddy residue. Links to them have been posted on this newsgroup (rec.autos.tech, which is where I'm reading this).

No question of that. Most of them are rather tight-lipped as to what exactly is in their "recommended" coolant.

Sorry, but with Dexcool, I have to disagree. There are known problems. They are admitted to by GM, it's primary promoter.

Cars with Dexcool have showed metal corrosion 2 years after leaving the factory.

Put whatever you want in your engine you bought it. they are additives that make me use the original Honda Fluids.

Change you antifreeze every 2 years what is that, about $20 Why spent 15 to

I hate to continue the argument, but this doesn't mean crap. But any AF in three million cars a year and some are going to show corrosion in two years. Be reasonable.

The question is whether there is a higher incidence of corrosion issues with Dexcool. Everything else is STRICTLY ANECDOTAL.

- Mark

There is also propylene glycol based anti freeze. PG is non-toxic.

The corrosion inhibitor packages used are compromises at best, and the protection they afford does not last forever.

non of the manuals say avoid colman coolent either. You know the blue stuff for cooling food. But I won,t try it. for all quotes there is an equally opposite quote