Is G-05 ok in an aluminium block engine?

[jmacmaster]

Would the coolant experts among you comment on the following? I've done a lot of research on antifreeze the past year or so and disagree with Subaru. I think that G-05 is the best all-around antifreeze and that more and more experts and auto manufacturers are coming to that conclusion as time goes by.

Subaru has its own brand of ethylene glycol antifreeze, and says that ONLY its brand should be used in Subarus. The only reason given in an article published in Subaru's "The End Wrench" magazine as to why ONLY Subaru's in-house brand of antifreeze should be used in Subarus is that one of the things that antifreeze does is protect against corrosion, how an antifreeze handles corrosion depends on the metals in the engine, and Subaru engines are all-aluminium with traces of other metals, such as steel and iron (in certain engine parts). To that I say: well, duh! Anyone with basic knowledge of engines knows that. This is an insufficient reason for even using only an ethylene glycol type of antifreeze, much less for using only the Subaru version of ethylene glycol antifreeze.

There are numerous engines, by numerous manufacturers, that are all or mostly aluminium. And all engines, no matter what the block is made of, have some parts (in addition to the engine block) made from two or more other types of metal. Ford Motor Co. and Daimler-Chrysler recommend G-05 antifreeze in all their vehicles and have for years. Does anyone want to claim that these companies don't make one or more engine blocks that are all-aluminium with traces of other metals, such as steel and iron? Of course not. So that means that Ford and Daimler-Chrysler think that G-05 is good for their all-aluminium engine blocks that have some parts that are other metals. Since these companies ALSO make engines with STEEL engine blocks and some parts that are metals other than steel, it also means that Ford and Daimler-Chrysler think that G-05 is good for their steel block engines as well as their aluminium block engines.

And of course, what the parts other than the block are made of will also vary from engine to engine, including of course among the engines made by the same company, yet Ford and Daimler-Chrysler recommend G-05 for all their engines.

In my opinion, this is simply another instance of a company trying to make money off the people it sells vehicles to by scaring them into thinking that its only safe to use "Genuine Subaru" parts, fluids, services, etc.

 

[G-MAN]

The block and heads of the 3.5 in my Chrysler are aluminum and it came from the factory with G-05 in it.

Mercedes has been making aluminum block engines since 1980 and G-05 was the factory fill way back then and has been ever since.

 

[Tosh]

I wonder what the Saabaru specs for replacement coolant.

 

[Ray H]

I'm unaware of any production engine cylinder blocks and cylinder heads cast from steel. There are quite a few still using cast iron for cylinder blocks and some still using cast iron for cylinder heads, though. As GMII stated, Chrysler's aluminum engines and many of Europe's aluminum engines do fine on G-05. According to several trade sources, Europe allegedly settled on G-05 (with a few notable exceptions) due to Europe's generally hard water and fear of loading an already mineral-laden coolant (the phosphates in Japanese coolants and older conventional silicated coolants) with even more mineral content from the local tap water supplies. The upshot from that combination is having mineral salts falling out of solution and causing mischief with water pump seals along with a conveniently insulating layer of insoluble slag on previously healthy, bare metal. The main thing I've learned is that type of antifreeze isn't as important as using some common sense in preparing a car for coolant changeout (thorough flushing - preferably with naturally soft or distilled/de-ionized water) and diluting the coolant concentrate with naturally soft - or preferably distilled/de-ionized water. Another thing I have learned about about antifreeze concentrate is that most types are 93-95% ethylene glycol (not an anticorrosive in its own right) and 1-2% distilled water. If you haven't kept up with the math to this point that leaves a paltry 3-6% left for whatever's used for corrosion protection and pH buffering. Even that number get reduced down to
1 1/2 - 3% after dilution to 50/50. By the percentages, the difference between any of the ethylene glycol based syrups is much more alike than different. The problem with cooling system maintenance isn't that it's difficult; it's just not, a> as sexy as trying the latest boutique engine oils, or b> as forgiving of negligence.

[ March 10, 2006, 06:17 PM: Message edited by: Ray H ]

 

[Eddie]

I think Subarus decision to use only their coolant was initiated because there was so many problems with mixing coolant types. I now see that most manufactures recomend that owners use ONLY their coolant for the sme reasons.

 

[Ray H]

The only "problems" with mixing antifreeze types is that if the weakest link's final concentration exceeds 10% in the blend, it'll determine the longevity of the mixed brew. The automakers' primary motivation for specifying their own parts and fluids is driven by their bottom line economics. The irony is that in many cases the automakers don't manufacture these components or blend these fluids themselves - their profits come from being an additional (read that as "u-n-n-e-c-e-s-s-a-r-y") step in the distribution chain. Automaker brands sold at stealership pricing are always the easier option. I don't happen to believe they're always the smarter option.

 

[Mr Nice]

I got G-05 right now in 2 different Hondas and all is well.

 

[Kestas]

Good posts by Ray.

Jmacmaster, your hunches are correct. I am intimately familiar with the metals that come in contact with the cooling fluid. And there's nothing magic about the metals used in Subaru's engine, or anybody else's engine. Nearly all manufacturers use the same basic metals for the cooling system. An aluminum block is pretty much the same thing as an aluminum head as far as corrosion goes. That's why I keep telling people it's unnecessary to use manufacturer or botique antifreezes (assuming all the old fluid is completely flushed out). Even IMcool.com recommends that repair shops only need to stock two antifreezes -- G-05 & Dex-Cool.