I ran across a great matrix chart of the various coolants available. Six coolants have checks in the HOAT column, and five of these are listed as meeting DaimlerChrysler OEM specifications.
If the chart is accurate, I'm curious why the Mopar HOAT coolant has a check in the w/out Phosphate column, but the Zerex G-05 does not. I had assumed these two coolants were exactly the same, save the orange vs. yellow dye.
It is a good reference chart and I am saving it for closer study. Dont know about the phosphate question. These formulations can be complicated to design, and still have everything work as it should. Some work I did about 10 years ago would have lead me to believe that a little phosphate was extremely desirable, especially where iron or steel is involved.
A type of corrosion is found where steel is exposed to water based systems (although they are oxygen free and elevated pH) that is easily stopped by a very small percentage of phosphate.
The reason why phosphate is not used in some of these systems is not intuitively obvious.
You could write cliffhanger novels.
When one has written scientific reports and presentations for years as I have, CYA English often results. Sorry.
In plain English, Ive never seen a system where water or water solutions contacted steel that would not benefit from a little phosphate. About 2% is normally enough.
I dont know why they choose to avoid it exactly, unless it is a tribure to political correctness.
Well, I *forgive* ya and all, I know where you're coming from since I frequently have to write in Regulatorese, but...what's the reason why phosphate is not used in some of these systems?
That is similar to my understanding
Ah. Thank you. I was wondering what you might have known but not elucidated when you said the reason wasn't intuitively obvious.
Some locales legislated against phosphate use for environmental reasons, with the idea that the phosphates will eventually end up in surface water and encourage algae bloom. Even those laws will normally allow small concentrations, but 'political correctness' sometimes leads formulators to avoid the use of the unpopular additive.
The whole OAT and HOAT situation arose as a quest to substitute some of the better additives with those which appear to be less toxic and less persistent in the environment.
The versions of those packages that were available at the time I was involved did not appear to have the 'robustness' of performance that the older technology could provide. (Now, that is really a CYA statement)
Yeah, well, here's mine:
OAT sucks, and I'm sometimes a slow learner. It took me four head gaskets, two heater cores and four radiators, on six cars, before I got the hint and quit using Dex-Cool.
DS
Probably. Phosphates lead to foaming in streams, among other things. There's been a big push to reduce phosphates in laundry detergents for decades.
Of course we're all supposed (nudge nudge, wink wink) to recycle our antifreeze as if it were just as nasty as motor oil... and then phosphates wouldn't be a problem, would they? Of course antifreeze is not nearly so bad as motor oil because it breaks down quickly. But it is toxic until it does so.
Here is the environmental attorney in me. Phosphates are a nutriant for plants. When it finds its way into our streams and lakes it promotes the growth of water plant growth. This is often not a good thing since the rapid unnatural growth of such plants can choke off the waterway and kill off useful species of plants and fish.
Richard.
Given a choice between rotting away my iron engine block or being more careful with used coolant, I'll take the phosphates and be careful.
Richard wrote:
Backing up to the fact that the chart shows Mopar G-05 as "phosphate free" but not Zerex G-05....
For what its worth, Zerex's web page on their G-05 DOES claim its phosphate free:
That is correct. It doesnt lead to foaming, as was previously suggested but it can support plant life, particularly algae.
I would not publicly knock any product unless I had personally tested it and knew it was a POS.
When you have brass in the radiator, tin/lead solder, iron in the block, aluminum in various components, etc, it becomes very difficult to arrive at a formulation which will do everything well.
Some of the organic acid technology LOOKS good, during short tests, but may fall short with time and exposure. It is not because the component is consumed necessarily. It may be because the nature of the corrosion mechanism changes as the system ages.
The simple answer is obvious, buy ethylene glycol (or propylene glycol) and DI water "straight up" and add your own additive package as needed. Of course although a 55 galon drum of glycol is available, the additive packs aren't.
Is there ONE coolant good for a Series 60 Detroit Diesel, a V-1710 Allison, a Honda Civic, a Ford Focus and a Isuzu powered Thermo-King reefer unit?
I've been using Dex-cool ever since stores started carrying Havoline Extended Life and have never had problems. This is with a VW, Toyotas (incl. a Nova), a Ford (Mazda engine), and a Honda. What did the manufacturers of your cars do wrong?
How much phosphate is introduced into lakes and rivers from antifreeze? My guess is much less than from laundry detergents.
How much pollution does each environmental attorney eliminate compared to each environmental scientist?
I bought a VW in the late 1970s and noticed it required phosphate-free antifreeze, which back then wasn't available except from VW dealers and a few import parts stores that carried BASF antifreeze. This VW had an aluminum cylinder head and radiator (and maybe heater core) but iron block. Other than hard water (I used only distilled), was there any reason for VW to prohibit phosphate?
What type of antifreeze do you prefer after the factory warranty is over?
How much pollution does each environmental attorney eliminate compared to each environmental scientist?
Well, when I worked for government the environmental scientist would identify a problem and a likely source, and the environmental attorney would write the regulations, recommend the statutes and direct the collection of evidence so that the source could be controlled. I never heard of anti-freeze being identified as a significant source of phosphate pollution in a water body or stream. Just don't drink the stuff.
Richard.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.