Interesting info on VW coolants found here http://jettajunkie.com/vw-jetta/showthread.php?2145-Coolant-types

Question: what coolant do I have? (or "what coolant should I use?")

Answer:G11 is blue (or bluish green). It's what came with most cars pre-1995, in about 1996 they started using the pink stuff (G12, below). G11 can be mixed with green stuff BUT it is not recommended at all. If it's blue in your expansion tank, stick with G11 and nothing else, just to be safe. Replace it every 2 years maximum.


G12 is pink. It cannot be mixed with any other coolant (except G12+ which is purple). It is supposed to be able to last 5 years before being changed (more frequent changes are suggested by vortexers, like every 2 years), and it has sealant and anti-coerosive additives.

G12+ is purple. It's new and it can be mixed in to pink coolant systems, it replaces G12 according to VW. In all other respects it is like G12.
Dexcool is orange. It cannot be mixed with any other coolant. It is very similar to G12 (though they cannot be mixed) in that it has a longer suggested time between changes (5 years) and has sealant and anti-coerosive additives. It's what I use, works great for me, others have had serious problems with it. Do not mix it with anything, stick with VW G11 or G12+ if you have the extra $20, probably worth it in the end.
Prestone is green. Most coolants are green, they are a-okay for most cars, but VW is not most other cars! This stuff is fine in VWs if all other coolants have been completely drained out, but why go to the trouble of removing a superior coolant and replacing it with something I wouldn't trust in my girlfriend's corolla? Use it if you must, but as a rule you should replace your original coolant with the same type, and for VWs that is not green.
*The G11 and G12 and G12+ coolants are all made by Petosin, a european company. If you really want to save a couple bucks you could buy petosin brand coolants instead, they go by the same color scheme (replace blue with blue, etc). VW sells it by the gallon, pentosin is sold by the 1.5 liter.
1 gallon = 3.79 liters
1 liter = .26 gallons


As for the additives, most parts stores (Kragen, autozone, pep boys, etc) will have them, use only those intended for aluminum heads. If you're looking to seal a leak, I suggest the stuff that comes dry with metal flakes in it. Get the prestone type if they got it, Bar's and others are also fine. Some suggest that a second dose might be necessary, I say it can't hurt. If you're looking to keep the temp down and prevent coerosion, then Water Wetter (by Redline) is supposed to be pretty good, but it's not necessary and in most cases it's not all that helpful (just more stuff that doesn't really help cool as well as just water can). What ratio to use:
VW recommends adjusting your mixture to your environment, if you need protection down to around -20 degrees F, then go with 60% H2O, 40% anti-freeze. If you need added anti-freeze protection (down to -35 degrees F) then go with 50% of water and anti-freeze.

And this on honda coolants was found here.

http://www.mr2.com/TEXT/HondaCoolant.html

This information was forwarded to me via several parties. Provided for your information.

Subject: Honda Anti-Freeze

Recently, several people have questioned whether the coolant (anti-freeze) sold by Honda and Acura dealers is different from the popular mass-market brands.

Honda has sent the information attached below to its dealers. While you might not expect the source to be exactly unbiased, it does provide technical information and justification for differences in their formula.

<senders address deleted>

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.

Chart here, entitled "Coolant Leakage from Water Pump Seal", showing Leaked Coolant Volume in ml as follows for each test duration in Hours:

24 hrs: Honda Coolant 0, Typical Silicated Coolant 21
48 hrs: Honda Coolant 1, Typical Silicated Coolant 36
72 hrs: Honda Coolant 2, Typical Silicated Coolant 47
96 hrs: Honda Coolant 2, Typical Silicated Coolant 55
120 hrs: Honda Coolant 2.5, Typical Silicated Coolant 56
144 hrs: Honda Coolant 3.5, Typical Silicated Coolant 57
168 hrs: Honda Coolant 4, Typical Silicated Coolant 58.8
192 hrs: Honda Coolant 6, Typical Silicated Coolant 63
200 hrs: Honda Coolant 6, Typical Silicated Coolant 64

[stalag: please note caterpillar tests for up to 6000 hours of run time. But this is instructive for what another coolant brand testing against a readily available standard does]

- 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.

(graphs here, showing roughness across the surface, with A a very wiggly line, and B a very smooth line)

- 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).

(note from XXX - I think I can guess whether the last paragraph, provided below, was written by the engineers or by the marketers...)

You can find less expensive coolants on the market, but now you can see why genuine Honda coolant is the only coolant approved for Honda and 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.

Pentosin produces most of VW auto group fluids. More information on this company can be found here.

http://www.crpindustries.com/pentosin/pressreleases/CATPEN11.pdf

So, should we put Honda coolant in our Fords? It appears to only be $14 a gallon anyway.

My recommendation for Ford Gold (G-05) or Caterpillar still stands. If you are more comfortable using the old style silicate/phosphate formula use that. However use distilled water for flushing and refill of your cooling system when recharging it. And be careful that you do not use a dexcool based formulation that is 100% prevalent with prestone or peak coolants.

Do you think I got really lucky with my 2000 Toyota Sienna considering I never serviced the coolant in it's entire 240K mile lifespan?

That your toyota did or did not need servicing depends on the coolant used by toyota in their cars. A few manufacturers use from the factory a lifetime based coolant. I would need to know more about the called for specifications for the toyota coolant used in your Sienna.

I don't know if it did need it or not but I never serviced it. I just replaced it when it go low.

I suspect you serviced the coolant by allowing the coolant leak that you had to help you renew the coolant. Since this a Ford forum pursuing this further should either be taken to PM or to the smoking lizard lounge for diagnosis and discussion.

Please correct me if I'm wrong but it's my understanding Cat ELC (along with Delo, Rotella and Texaco, Zerex HD ELC's etc...) is Dexcool with added/additional Nitrites and Molybdates for wet liner cavitaiton protecion.

The only non Dexcool(2-eha) coolants are GO5, Conventional Green, Peak Global Liftime, Peak Final Charge, Detroit Diesel Power Cool Plus(Peak Final Charge) and Fleetguard ES Optimax.

Again please correct me if I'm wrong. I hope I'm wrong I can get Cat ELC for cheap at Rush next to my shop.:)

Cat ELC is NOT a Dexcool variant. It rather is more closely related to G-05 with slight variations in chemistry to match Caterpillar's requirements for longevity.

And from my chemical knowledge after having spoken with both Peak and Prestone, all formulations of both Prestone and Peak coolants are variants of Dexcool without exception and to varying degrees have the same issues as Dexcool does. The sole exceptions to this may be the coolants marketed for trucks but this has not been extensively checked out. Furthermore there are Dexcool truck coolants that may exist because GMC trucks did come with Dexcool in their cooling systems. Truck coolants due to the supplemental coolant additives either need the coolant base anticorrosion package to be the silicates/phosphates of the conventional green coolant or must meet the Caterpillar ELC-1 specification (it is unknown if Dexcool has an supplemental coolant additive). By the way, a supplemental coolant additive (SCA) designed for the conventional coolant is not compatible with the Cat ELC-1 and vice versa. However to be doubly sure, check to see that the conventional truck coolants contain silicates/phosphates before attempting to use. A truck coolant of this type just contains more silicates/phosphates than does the automotive variety. It will also be more abrasive as a result. Caterpillar ELC-1 licensed coolant and the Cat ELC-1 coolant also have a specific SCA for that coolant and what is even nicer the anticorrosive chemicals are totally dissolved and will not act as an abrasive in the cooling system.

The chemistry as to why Dexcool is an issue is not just 2-ethylhexyladipate, but is also the dicarboxylic acid chemicals used in its formulation. In either basic solution or acidic solution the combination of an bisalcohol like ethylene glycol and a carboxylic acid like 1,4-benzendioic acid will cause polymerization in the block. This reaction is further catalyzed by the presence of metal oxides that are found in the cooling system on the metal surfaces. This is what causes the sludge to occur that plugs up cars containing a Dexcool charge in their cooling systems. This is why I cannot under any circumstances recommend most coolants put out on the market.

The nitrated organic acid technology actually chemically while still basic for the anticorrosion protection, passivates the chemistry making the esterification reaction that is so bad in Dexcool formulations from even occuring. This is why I recommend Zerex origional green coolant, Zerex G-05 coolant, Zerex ELC-1 coolant, The proper Motorcraft coolant purchased from the dealer, the Caterpillar ELC-1 coolant (which I used), or any other coolant clearly marked as to the type of coolant it is. Dye color cannot be relied on as an indicator of compatibility and this is at the express statement one of the major suppliers of coolant dye to the coolant formulators. Any coolant marked as compatable with other coolant types needs to be avoided at all costs. More trouble has occured because of this than you would be led to believe.

No matter what coolant you choose, make sure it is the same stuff that originally came in the car. Because of chemical incompatibilities it is not recommended to change coolant types without following the procedure outlined in my first post in this thread. Also for the same reasons, if you are going to change coolant types, follow the Caterpillar recommendations and you will have no issues whatsoever in changing from one coolant type to another. This is a tried and true method that works, and chemically it is the best way to proceed. However most mechanics do not like it because of the additional time it takes. Proper coolant changes are not just hooking up a machine and changing an old charge for a new charge, but is in taking the time to fully flush all the old coolant out and replace with fresh uncontaminated coolant for the best anticorrosion protection. In my case the cost at the dealer for replacing my head gaskets and the intake manifold was $3200. That is a lot of money and was due only because the prior owner never maintained the coolant properly. I myself in any other vehicle I have owned, have always maintained the coolant integrity and have never had a coolant related failure until my Lincoln Town Car.

Thanks for the info! I thought Cat, based on what I read, was an OAT and not an NOAT. Everything I read states that it is Nitrate free and relies on Carboxylic acids just like Dexcool.

Not trying to be argumentative just trying to learn something.

General info on cat coolants can be found here. this link includes information on who recommends this coolant in addition to Caterpillar

http://www.louisiana-cat.com/assets/uploads/elcfaq.pdf

Information on the ELI concentrate for refreshing Cat ELC-1 coolant

http://parts.cat.com/cda/files/3055800/7/PEHJ0263.pdf

And an interesting read on bobistheoilguy forum that you just joined is the following posts.

http://www.bobistheoilguy.com/forums/ubb...amp;type=thread

I will confirm I have seen the same information expressed by the poster Extreme Duty.

Does this answer your questions. Cat ELC does contain sodium nitrite which will also inhibit esterification reactions as well as having other benefits.

How do you know Cat ELC is not a Dexcool variant but a G-O5 variant? It would appear based on the following information that Cat ELC, made Texaco is/was originally called Dexcool Hd - Nitrited Dexcool.

http://www.penray.com/images/01.010.pdf

Based on the following links from Penray it would appear there are only four inhibitor packages used here in the US

Inhibitor package 2798-Dexcool:
http://www.penray.com/images/2798_InhibitorSheet_3.pdf

Inhibitor package 2798N - nitrited Dexcool package that is CatELC and compatible with Cat ELC:
http://www.penray.com/images/01.010.pdf

Penray Flyer stating that 2798N is Cat ELC:
http://www.penray.com/images/98.002.pdf

Penray 2705 Inhibitor package - Hybrid Ford/Chrysler:
http://www.penray.com/images/INH2705Flyer.1206.pdf

Penray 2792 Inhibitor Package - Fully formulated Convetional:
http://www.penray.com/managex/index.asp?x=313&y=314&articlesource=314&navID=

All Inhibitors: http://www.penray.com/managex/index.asp?x=313&y=313&articlesource=313&navID=

I don't think its a big deal if its(Cat ELC) Dexcool or not based on your statement that if it is nitrited it will mitigate any compatibility issues. I certainly defer to chemical expertise.

Edit: Cat MSDS list Texaco as Manufacuter - https://www2.itap.purdue.edu/msds/docs/12003.pdf

Excellent set of links here. In addition, information on Penray looks to me that this company is an original additive supplier for coolants much like Lubrizol is for lubricants. Chances are Penray technology shows up in many coolants much like Lubrizol technology shows up in many lubricants.