Good point! I try not to foul things up with the wrong coolant, but I wasn't aware of the problems with Ethylene Glycol when i started using Sierra! Reading these posts and servicing my own cars, I realised just a couple of days ago what the Mercedes Benz authorised coolant was completely by accident! When I did some further research, I found out the difference between Ethylene Glycol and Polypropelene Glycol! It suddenly made sense. If you have plastic end tanks or cooling system parts, go with a polymer based coolant! After all, plastics are made with polymers!! This all started coming together when as a trucker, I noticed Peak has been made especially for truckers because truckers trucks have had radiators made with plastic end tanks for years! I could never figure out why I never had the same problems that every one else did with the widely available green stuff even though I kept looking for it! Then I realised that I have been using a totally different formula entirely. There are only a few companies making antifreese for several different brands and started gathering brand history and posted my findings and opinions here. I hope this helps! Keep commenting!

I read the owners manual for my '84 300D and it recommends that I use MB coolant as MB can guarantee it to be safe in their product. The manual then goes on to say that there are many other coolants available that are perfectly safe to use but since MB has not tested them they cannot recommend them.

So if MB has not approved a coolant is it not compatible? Not according to MB. I like and use Rotella ELC which is a heavy duty diesel coolant designed for diesel engines. I'm not sure whats in it but last time I checked it stated it was approved for ALL cooling systems. Its red and considered an extended life coolant. I was using it in 3 vehicles so I was purchasing it by the case as this makes servicing easy. So far so good, likely the body will rot away before I have a cooling problem. RT

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

Who told you that ??
Even MB antifreeze right out of the jug will leave a white residue after a leak (or spill)

I also will not try to save a few bucks on other than MB antifreeze in my '87 300D's w/ the aluminum head. What can happen (as I learned from a senior MB mechanic at a local dealership) is that all antifreeze degrades over time and the additives that protect metal from electrolysis drop in effectiveness until the aluminum starts eroding. Its a well known penomena in gassers also.

617 engines with iron heads are not affected in this way but other parts in the cooling system may be. I have been guilty of using some of the red stuff in one of my iron monsters, I doubt any coolant on the market would harm the heads in one of them, unless used in 100% solution.

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

Yup, namely things like the plastic radiator neck, and aluminum parts in the cooling system.

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'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.

Well, now you know someone or at least of someone! I endured this last summer without AC in my 240D. And I'm not looking forward to the next one but I doubt I'll have the system working by then so, oh well. I guess I'll just have to grin and bear it again.

- Peter.

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2021 Chevrolet Spark
Formerly...
2000 GMC Sonoma
1981 240D 4spd stick. 347000 miles. Deceased Feb 14 2021
2002 Kia Rio. Worst crap on four wheels
1981 240D 4spd stick. 389000 miles.
1984 123 200
1979 116 280S
1972 Cadillac Sedan DeVille
1971 108 280S

Folks,
It may be true that Peak manufactures the "Sierra", and "Global....whatever" coolants.....but I am unsure if they actually manufacture the MB coolant.....if they in fact do manufacture the MB coolant, there is no guarantee that their other coolants meet MB specs....

From what I have read, here and elsewhere, and in MB publications......the basic MB claim is that the MB coolant is formulated for the specific alloys used within the MB engines.....please note that I have never seen either Gasoline or Diesel engines singled out....just MB engines....

From personal experience on German built ships, the German engineers use some pretty wild alloys in various applications....but especially where coolant piping and heat exchangers are concerned.....an American shipyard caused us big time problems by simply brazing with an unapproved material.....caused all sorts of dissimilar metal problems and caused some of the ingredients within the piping to plate out......so Unless I know absolutely that a coolant is MB approved.......I will just use the MB coolant that I get at the Dealership that is a bit over 60 miles from here......I plan ahead, and keep some for emergencies......

SB

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Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG

However,

I used to be the product manager for a large chemical company for both Ethylene and Propolyene Glycol. Ethylene, Ethylene Oxide and Glycol are in much larger capacity than PG and its' pre-cursors, the primary reason EG based antifreeze is less expensive. PG, as I recall, has more favorable properties as a coolant as well as its' obvious environmental benefits,,, the stuff is in a great many foods, cosmetics and pharmaceuticals... you can drink the stuff. We tried like heck to sell PG based coolants back in the 80's, but the "green" movement wasn't really in gear and the price points for EG based coolants were too low, still are, for broad use of PG based coolants.

The real issue here is the corrosion inhibitors. All coolants have blends of corrosion inhibitors specific to the metals in the application, be it GM, Ford or Mercedes. These inhibitors are heat sensitive and break down over time, thus the need for coolant replacement at regular intervals, as there is no real good way to recharge automotive coolants. Also, heat creates an acid, as I recall Oxalic Acid, over time in EG based coolants, thus the etching and corrosion. I don't thing EG itself is necessarily acidic, but I could be wrong.

MB coolant is specific to the metals in MB motors. Other companies, like Peak, Prestone, have inhibitors that apply to a broad range of metals,,,, kind of the master of all but the expert in none, such that they have a broad applications across a broad base of manufacturers.

Based on my experience, the best deal is MB coolant changed in regular intervals. The next best is any coolant changed in regular intervals. That last is any coolant which is not changed regularly as the inhibitor package loses its' punch over time.

In the end, it is less about the type of glycol, and more about the inhibitor package and regular coolant changes.

My two cents.

http://cgi.ebay.com/ebaymotors/SP-Diesel-94-PowerStroke-Coolant-Filter-Kit_W0QQitemZ150068440252QQihZ005QQcategoryZ33663QQcmdZViewItem

If the test strips work and the inhibitor package sold is consistent with the starting coolant, I guess in this case Navistar's blend, then I guess there is a way to recharge coolant inhibitors. Maybe not an easy way, but a way none-the-less.

I would still feel safer in non=commercial applications buying the necessary coolant to replace consistent with manufacturer's intervals.

Who needs to travel? All you need to do is click or call Phil up and some shows up at your doorstep.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

i don't think so. i spilled some 50/50 g-05 while filling up my coolant tank and left some white stains around where i spilled it when it dried. therefore the interior of the cooling system has nothing to do with them white stuff.

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'85 300D Turbo - CA Version

This subject has been discussed voluminously over the years. Boils down to those that, for some unknown reason, believe they are smarter than the mfg., in this case MB. They go to great lengths to save some silly amount of money over the coolant change period. In exchange, they risk unseen damage inside the engine. In my opinion, someone saying that they have been using green coolant for years and have seen no damage has little validity. I choose to believe the experiences of mechanics who actually have seen the results of improper coolant when engines are dis-assembled.

Others simply follow the manufacturer's recommendations.

Zerex G-05 mfg. by Valvoline is identical to the MB coolant. However, it is
hard to find at retail. According to Valvoline, any NAPA store can order it for you.

Steve

Well my 80TD just starting getting a little hotter than usual (maybe 90 celsius) today while doing a lot of around town stuff. Normally I just cruise it to and from work so never noticed it get hot. Also my heater does not work. I know the W123 has the fabled ACC system known for failing, but I heard that an improperly functioning thermostat can be a cause for the heater not working. I figured I might as well replace the thermostat and hopefully kill two birds with one stone.

Grabbed a new 80 degree tstat from Napa Auto and a bottle of Sierra, which was the only brand they carried that was made with Polypropelene Glycol. It was because of this discussion that I decided Sierra might work out just fine.

I remember I had a similar decision to make when I changed the coolant in my 87 Syncro Vanagon, as their was people who only suggested that you use VW certified coolant and those that said coolant made with Polypropelene Glycol would be fine. I opted for Sierra back then and here I am doing it again.

Maybe it's because I don't plan ahead and always change my coolant on a Sunday, or maybe it's because I trust that Sierra is a good brand, either way though I'm glad this discussion is going on.

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-justin

1987 300TD, 1987 300TD
2008 R32, 2000 Passat Wagon

For what it's worth.... PEAK GlobalLifetime has MB listed in their "Recommended For Automobiles With The Following Antifreeze Specifications:" ("Mercedes Benz DBL 7700 ") - I'm not sure what DBL 7700 means though.

Must be the MB coolant specification... sounds good to me.