Yes, it's true that Mercedes does say it's safe to use Prestone antifreeze in your Mercedes. But, they state it in a subtle way.
On the Model 123 Service Manual Library Disk, they have the Owners Manual for the 1989 560SL. This manual is only an example of all their other Owners Manual,and is applicable to all models. Let me quote from page 90 of this manual and what it says about coolants. I am not making this up. Check it out.
"While there may be a number of anticorrosion antifreeze/coolants available which WILL PROVIDE the requisite(required) protection, all such products have not been tested for Mercedes-Benz vehicles. The following product, however, is recommended for use in your car: Mercedes-Benz Anticorrosion/Antifreeze Agent."
Because the Mercedes antifreeze market is relatively small, Prestone and the other major MFGs of antifreeze have not seen fit to pay Mercedes to test their products.
The last bottle of the MB antifreeze I saw was orange in color.I don't think it even said anything about the stuff called Glysantin G-05. Zerex is orange. Both are made by Valvoline Oil, a division of Marathon-Ashland.
I just checked the owners manual on my 1982 300D-turbo and 1983 300SD. Both have the same quote as above about the coolant. As for my 1977 300D, the manual only states, and again I quote; "Any Mercedes-Benz service station will readily advise you on recommended antifreeze brands."
When I bought my first MB (1967 200D), the dealer said I could use any brand of antifreeze I wanted to use. I chose Prestone and I have used it for 34 years in all the MBs I have owned. I have never had any problems with it...
Bill Lewallen; Lexington,Ky.
Home of Valvoline Oil-The maker of MB antifreeze,but It's not made in Lexington...

Bill,

Give us a break on evangelizing the Prestone. There is nowhere that Mercedes-Benz EVER mentions Prestone by name, and the "disclaimer" you refer to, stating that "there may be a number of anticorrosion antifreeze/coolants available which will provide the requisite protection", is so blatantly open to interpretation that it's laughable. Also, you may not be aware that there are laws pertaining to automobile manufacturers dictating the use of specific brands of additives, fuels, oils and antifreeze. That is specifically, and quite obviously why that statement was worded that way...

__________________

Scott Longston
Northern California Wine Country...
"Turbos whistle, grapes wine..."

Scott and others,
I figured that subtle statement made by Mercedes in their owner's manual about antifreeze, would raise some dander. The only word I added was the word 'required' in parenthesis. And then only because I thought some of you might not know what the word requisite meant. The word 'may' is in the original quote. Let me quote from the Owners Manual again. I will also quote the preceding paragraph;
"Your vehicle contains a number of aluminium parts.The use of aluminium componants in motor vehicle engines necessitates that anticorrosion/antifreeze/coolant used in such engines be specifically formulated to protect the aluminium parts.(Failure to use such anticorrosion/antifreeze/coolant may result in significantly shortened service life."
"While there may be a number of anticorrosion/antifreeze/
coolants available which will provide the requisite(again I insert the word 'required')protection, all such products have not been tested for MERCEDES-BENZ vehicles. The following product, however, is recommended for use in your car:MERCEDES-BENZ Anticorrosion/Antifreeze Agent".
The MB antifreeze is made by Valvoline Oil and is now orange in color. Valvoline also makes Zerex. It too is orange.
I have no stake in Prestone, nor do I own any shares in Honeywell(parent company of Prestone).
I buy the store brand of antifreeze. It is green and is made by Prestone.
Bill Lewallen;Lexington,Ky.
Home of Valvoline Oil, but the orange stuff for Mercedes is not made here.

Bill like you I use the store brand, and over the years have had a number of aluminum parts in engines, and Prestone has never failed me. So many of the oils and other engine additives like anti freeze are manufactured by a limited number of companies for many companies that like to sell their own brand and value added(so called) lines of auto parts or supplies.

Am I missing something?

Why not just use exactly what's expressly specified in the manual, and avoid the need for debate, or the need to rely on "subtleties" in the owner's manual, all together?

Please don't tell me its to try to save $10 per year on anti-freeze . . .

Here's the hard facts: The antifreeze industry is in such a state of change at this time due to the advances made by BASF in corrosion inhibitor production for antifreeze agents that it will be just a matter of 5 to 10 years before we will not see antifreeze containing phosphate anticorrosion inhibitors anymore, and Mercedes was the pioneer in this area of advanced corrosion inhibitors. The green color is just a dye, and there actually are over 15 individual colors of antifreeze available today.

GM is dumping the Dexcool specification in favor of a new coolant formula containing a Glysantin derivative. Ford will also be having a Glysantin derivative anticorrosion agent in their antifreeze coming out in their new vehicles, and Chrysler is already specifying a Glysantin anticorrosion agent in their antifreeze right now. BMW, SAAB & Volvo all use a Glysantin Derivative anticorrosion agent in their factory fill antifreeze. There's a damn good reason that this is happening, it's because it works better! Oh, and all of these antifreeze products are being produced by Zerex.

__________________

Scott Longston
Northern California Wine Country...
"Turbos whistle, grapes wine..."

Brian K,
You certainly did miss something. Read your Owners Manual again. It states that there a number of antifreezes that will provide the same protection as the Mercedes-Benz antifreeze, but have not been tested by them. This stuff MB sells for $13/gal is no better than the antifreeze you can buy off the shelf for about a third of the price. Whether It's tested by MB means nothing to me. The alternate brands are tested somewhere, because they all state they are safe to use in any type of engines.
The "new" MB antifreeze lists the ingrediants, but says nothing of the Glysantin G 05 formulation. It used to be clear in color. Now it's orange. So is Zerex. Both are made by Valvoline Oil, which is a division of Marathon-Ashland Oil. Zerex is safe to use in your Mercedes. Says so on the bottle. The label states that Zerex is safe to use in any engine.
I don't care about the price. I buy the best products at th best price. Been doing for the last ** years. Around here we call it Economics 101, or just plain smart shopping.
I care not, which product you use. If you want to believe that Zerex is better for your car, then by all means, use it...
Bill Lewallen;Lexington,Ky.
The Blue Grass State; but the grass is really green-like our antifreeze...

So what am I missing? I am still confused on this.
Is all of this debate over saving $8 per gallon on anti-freeze?
How many gallons do you go through in say, 2 years?
Two?
So all of this debate and argument to save $8 per year?
Or double that? $16 per year?
It sounds like you are only arguing about this because non-MB anti-freeze is (literally) a few dollars cheaper.
But then you say "I don't care about the price."
Thus the confusion.
Are you saying the non-MB stuff is *better* than the MB approved stuff?
Because that would be an interesting argument that I'd like to hear more of.
But if your only point is to save $8 per gallon on anti-freeze that is not better, but only maybe equivalent, that is not very interesting. You may very well be right, but there ain't no way that I am going to move away from MB approved *anything* to save $8 per year.

Brian K. and others,
The only thing I am trying to get across to all the MB owners, is that the owners manual states "there are a number of antifreeze/coolants available which will provide the requisite(required)protection as the Mercedes-Benz antifreeze agent." I don't care which brand of antifreeze you use. Go back and read your owners manual. If you don't have the owners manual, contact your dealer. Our local dealer used to give them to me. And I do have a stack of them.
The way I understand what the manual states about antifreeze is that we can use just about any brand of antifreeze we choose, as long as it provides the requisite (required) protection.
Who knows maybe I will convert to Zerex. It's orange in color, which just happens to be the color of my alma mater; The University of Tennessee...
Bill Lewallen;Lexington,Ky.
Home of The Rolex Three Day Event...

Bill you are fighting a losing battle here. These guys have money to burn and can't figure out how to do it unless they pay the inflated MB prices. I am in total agreement that there is little difference, all manufactures recommend their own specific brand, because they charge inflated prices for it. It would be an issue for me if I had to pay two or two and a half times the needed price for anything MB or otherwise.

The battle on the antifreeze issue has been won-lost, and I don't know who won or lost. Those with all the money, or the rest of us with at least a 5th grade education who can read and interpret what we read. The owners manual clearly states that there are a number of antifreeze/coolants on the market that will provide the requisite (required) protection. It is only "recommended" that you use the MERCEDES-BENZ antifreeze.

Will write more later. I have to help a friend put a new hood liner on and flush out the cooling system, and guess what? He's using the "recommended" MB antifreeze. It's orange in colour just like Zerex. That's his prerogative and money...

Bill Lewallen;Lexington, Kentucky. Home of the Rolex Three Day Event...

Hey, I've worked hard all my life so I can afford to blow an extra $8 every 2 years on anti-freeze!
I thought you guys were kidding at first . . .

Brian K,
We are not kidding. Go read your owners manual again. Maybe you will understand it this time. I care not which brand of antifreeze you guys use, nor do I care how much you pay for it. Being such a fastidious Mercedes owner, you probably buy MB batteries;MB washer fluid;MB brake pads;MB brake fluid and even MB antifreeze, when all of us 5th graders know that Mercedes does not make any of these products. However, they do recommend certain products for all MB owners to use. But they do not say we must use the products they recommend. They state in the owners manual that there are other products that are just as good as the ones recommend by them. Again I say read the manual and see what it says. Even though they recommend using their antifreeze, they leave the choice of which ones to use up to us as long as it meets the protection needed for MBs.
Well we got the new hood liner on and also replaced the trunk seal.He got those parts from some place in CA. We will flush the cooling system next week. And yes,he bought the MB antifreeze from our local dealer. It's orange just like Zerex and both made by Valvoline Oil. He's a strange customer. He buys MB antifreeze from the dealer, but buys the hood liner and trunk seal from CA. Of course he saved over $100.
Bill Lewallen;Lexington,Ky
Home of RDC Bearings

William,

It appears that only people from UT(either University of Texas OR the University of Tennessee) are going to understand the attraction of Orange anti-freeze. But even we are able to separate this and save money where we can.

This debate is very similar to the 10,000 oil debate posts we've seen. If you're using a decent quality fluid AND changing it on the proper schedule, your car will live many years and miles.

Larry,

You make the point about the MB antifreeze and other MB products better than I can. All I'm trying to say is for the owners to just read their owners manual and make up their minds on which products to use in their Mercedes. The manual states that there are a number of antifreeze/coolants that will provide the requisite(required) protection. I care not what the cost is. I always buy the best product that will do the job at the lowest price. If $13/gal is the best price for the best antifreeze, then I will buy it. But the MB antifreeze is not any better than of lot of other brands on the market, and the other brands costs less
I just found out that Autozone sells their own brand of antifreeze(made by Zerex) $0.50 less per gal than the Advanced Auto brand(made by Prestone). Of course we all know that Valvoline Oil makes the MB antifreeze and also makes Zerex, and both are orange colored. Since orange is my favorite color, I may just switch to the Autozone brand the next time I change coolants. It (Zerex)provides all the requisite protection required for Mercedes...
Bill Lewallen; Lexington,Ky.
Home of Valvoline Oil,But none of their coolants are made here...