Green Vs Red Coolant

[wandawoods]

to follow up the discussion on this thread (Radiator Fluid Flush?!?) :

http://us.lexusownersclub.com/forums/index...?showtopic=6383

I think this warrants a new thread.

Although I am no chemist nor do I intend to introduce a chemical lesson here, but I do want to get the bottom of this confusing issue: green vs red coolant. please read this excerpt from:

http://www.babcox.com/editorial/tr/tr110046.htm

(it's a very good article, you should really read it if you have concern about this issue)

Corrosion Inhibitors (the only chemical differrence between green and red)

=============

Because coolant is in constant contact with the metal parts of the engine and radiator, some type of corrosion inhibitors must be used in the antifreeze to protect all metal surfaces from electrolysis. That includes cast iron, steel, aluminum, brass, copper and lead solder.

Most conventional antifreezes formulated for the North American market, whether green or yellow in color, contain inorganic salts of borate, phosphate and silicate to prevent rust and corrosion. The additives create an alkaline coolant mixture that typically tests at about 10.5 on a pH scale. The silicates form a protective coating on metal surfaces, and are especially good at protecting aluminum.

To ensure that coolant remains alkaline for a reasonable length of time, there must be enough corrosion inhibitor to neutralize the acids formed from glycol degradation that occurs over time. This neutralizing capability is called "reserve alkalinity," and it varies depending on the type and quantity of additives used in a particular brand of antifreeze.

Heat, dissolved oxygen, minerals in the water, and corrosion inhibitor reactions at the metal surface gradually use up the corrosion inhibitors. And once depleted, the coolant becomes acidic and corrosion accelerates. The secret to preventing internal corrosion, therefore, is to change the coolant before all the reserve alkalinity has been used up.

Periodic coolant changes are especially important with today's bimetal engines and aluminum radiators and heater cores because the different metals create a miniature battery cell that promotes electrolytic corrosion. Aluminum becomes the sacrificial anode, iron the cathode, with the coolant serving as the charge-carrying electrolyte.

The higher the percentage of dissolved minerals and salts in the coolant, the better it conducts electricity and the faster the aluminum is eaten away. As long as the corrosion inhibitors are working, the process is held in check. But once they're used up, corrosion starts to eat away. The most vulnerable components are usually the thinnest, which include the radiator and heater core.

-- end quote --

it turns out Toyota red coolant is based on OAT (organic acid technology) additives in Ethylene Glycol. the OAT has been surrounded by problems and controversies for GM and Ford, but the main advantage of OAT technology is extended service life: up to five years or 150,000 miles providing that it should never be topped off or mixed with non-OAT coolant such as silicates based green coolant (two years or 30,000 miles).

my conclusion:

1. it’s perfectly safe to refill with regular green coolant (phosphate/silicates additives) if you perform a complete 100% flush of red coolant (OAT additives) like at the time you need to change timing belt/water pump or any radiator related works.

2. it seems that green coolant provides better protection for aluminum but red coolant provides extended service life.

3. it’s absolutely crucial you must do 100% flush if you decided to change coolant type. if you are not sure about whether you can achieve 100%, you can either stick with the same coolant type or bring your Lex to professionals.

4. never, never top off or mix with green coolant if you got red in there already

5. use only distilled water to do the 1:1 mixture. the trace contents of tap water or mineral water can react with corrosion inhibitors in the coolant (green or red) and significantly reduce their protective effectiveness.

hope this info helps to clear out the coolant confusion.

[SKperformance]

i would disagree with your statments

and also counter with the reasoning that no where in your post did it state what the difference of the red and green is beside oraganic or not

it only mentions the green make up but not the difference

who has had a problem with the red

anyone? i think not,at least not with a lexus a gm is a whole different animal

if you feel better saving a couple dollars for the green then go ahead

[99lsguy]

The higher the percentage of dissolved minerals and salts in the coolant, the better it conducts electricity and the faster the aluminum is eaten away. As long as the corrosion inhibitors are working, the process is held in check. But once they're used up, corrosion starts to eat away. The most vulnerable components are usually the thinnest, which include the radiator and heater core.....

5. use only distilled water to do the 1:1 mixture. the trace contents of tap water or mineral water can react with corrosion inhibitors in the coolant (green or red) and significantly reduce their protective effectiveness.

wanda,

I think this distilled water mix @ 50/50 is very crucial also. It is the only type of water that goes in my LS :D

99

[steviej]

I do find it interesting how Lexus and Toyota dealerships are starting to flush the red coolant before 60k miles or 5 years. My service manager says it is because they are not feeling comfortable with the "long life aspect" and it is cheaper for them to flush it out sooner then to replace a crapped out radiator towards the end of a warranty.

steviej

[wandawoods]

and also counter with the reasoning that no where in your post did it state what the difference of the red and green is beside oraganic or not

it only mentions the green make up but not the difference

if you had read the thread:

http://us.lexusownersclub.com/forums/index...?showtopic=6383

you would notice we had listed all ingredients labeled on red and green.

the only difference is OAT is added to red coolant, and green is using phosphate and silicates. other than the differrent corrosion inhibitors, they're both based on ethylene glycol. by some counts, phosphate/silicate forms better protective coating on alluminum.

it's not the matter of $6 vs $23 per gallon which I did buy, and of course it's my own business to use whatever I want to use, but I just didn't like to be misled that green coolant can cause corrosion or damage to your radiator which had been said God-knows how many times in the forum.

[jzz30]

personaly i use prsetone in all of my cars and i have had no problems with them 14 years and running( like my LS) its green and it works its EG base and thats what the manual calls for and my all aluminum radiator has lasted 10 years and could have lasted longer but old leaves that collected a the bottom traped moisture and started to corrode the aluminum so thats the only reason why i changed it.

my opinion is use whatever based coolant the manufacture suggests and change it on the schedueled basis.

[monarch]

.

Toyota and Lexus engineers build the most reliable and durable cars

in the world. Right? So how come everyone thinks the engine oil, antifreeze

and brake fluid they put in the cars at the factory isn't world class?

Owners who follow the car maintenance advice of the Toyota engineers

and use genuine Toyota antifreeze are rewarded in this way:

http://www.saber.net/~monarch/lexredbene.jpg

Owners who succumb to the advertizing and faulty information provided

by "car care authority" type internet web sites may end up using aftermarket

antifreezes which can do horrible things like this:

http://www.saber.net/~monarch/deathcool.jpg

While every Toyota and Lexus leaves the assembly line ready to do

30 years or 500,000 miles of troublefree service, a majority of them

end up in junkyards at between 150,000 - 300,000 miles because

critical components like their radiators end up looking like this

http://www.saber.net/~monarch/radafter.jpg Things like this wouldn't

happen if owners and car repair shops maintained Lexus'swith factory

original parts, fluids and filters.

While genuine Toyota red antifreeze has been the factory fill in every

Lexus ever made, in more recent years, Toyota and Lexus owners manuals

have been more adamantly been recommending the exclusive use of genuine

Toyota antifreeze. Here is what the 2004 Lexus manuals say (with my

notes added in green text): http://www.saber.net/~monarch/lexusSLL.jpg

I think its a shame so many Toyta / Lexus owners think Toyota recommends

their own special antifreeze just for the sake of short term antifreeze profits instead of

the long term reputation of the Toyota / Lexus name.

[jzz30]

i also agree about useing toyota coolant only but well most of the time its sunday and the dealer is closed and well i have had absolutely no problem with what i use.

[VMF]

i also think the difference is also in the percentage of ethylene-glycol in the mixture. toyota recommends that it should be between 50% and 70%.

[99lsguy]

Just called the local Toyota Dealer - Parts Dept.

Toyota Long Life Coolant is $15 / gallon.

It is not premixed 50/50 with distilled water - so that will cost an extra $.95 /gallon.

I'd say $32 well spent....

99

[98 LS]

Right on 99 ...............

That's the way I'm going as well.

[mobilyte]

message deleted

[UCF3]

Alright, this is what I say. Since so many of us prefer to use the Toyota coolant, can anyone tell me who makes the Toyota Coolant?

Wandawood and monarch:

Could you cite the source of your research? I'm just a little curious.

Now, I'm going to add my two cents into this conversation. I personally can not guarantee what Peak, Prestone, and some of the other brands mentioned in the two threads I've been reading, put into their antifreeze. Toyota does guarantee their products, but since Toyota doesn't make their own brand of oil I need to know what brand are they using.

From what I've learned over the past 5years of working in the race world, the best of the best oils, and chemicles are made by Redline, Motul, and Mobil 1. FIA, SCCA, INDY-Cart, and a bunch of Motorcycle racing leagues' sponsor the above three more than anything else.

My business partner is a former AMA Rider, and his team used Redline. Since I'm starting a business soon, the only oils and chemicles I intend on carrying are Redline, Mobil 1, and if I'm lucky Motul.

I'm probably going to take the Prestone Antifreeze out of my cars soon, and probably drop some Redline WaterWetter. Best of the best.

[99lsguy]

quick question...how do i flush the coolant that's still in the heater core? i know there are two drains on the engine block and one on the radiator, but if up to half the coolant is still in the heater core, what do i do??

I think the coolant will drain out anyway. It must, because in the lexus manual it says (after refilling) to open the heater valves (or turn your climate control on HIGH HEAT) and run till warm. Then recheck level and top off.

[mejojo]

As for a full flush, you could keep adding water and then run that out until there's no more color.

The purist would do the flush with distilled water so that any leftover water in the system would be ready for the new mix.

Joe

[K9crew]

Because coolant is in constant contact with the metal parts of the engine and radiator, some type of corrosion inhibitors must be used in the antifreeze to protect all metal surfaces from electrolysis.

The authors of this article aren't chemists or corrosion experts either ... dissimilar metals in an electrolyte can result in GALVANIC CORROSION not electrolysis!!

:)