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1991 MKIII Turbo Stock
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New supra owner here, pretty much a novice. My coolant light is on, not sure if I’m going to drain or just top it off yet. Engine is hot so I’ll check tomorrow. I have PEAK green prediluted coolant on hand and I’m wondering if this is okay to use. I can’t contact the previous owner but I would assume he used Toyota red. This PEAK green has silicate in it which I have heard negative things about. Looking for any advice, sorry for my naivety. Pics of the coolant provided below
261144
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I’d check what’s in it first. Should be running Toyota red. Some coolants can’t be mixed, not sure if that would be the case here. It’s summer so if it’s just a little low you’d probably be better off just topping it off with water until you can get what you need.
 

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Do not use that coolant, it's the old old style that contains silicate (says it on the label). When I was trying to answer this same question it seemed to be the consensus that the silicate based coolants are for vehicles older than ours. In "newer" cars the silicate is too abrasive and can damage the water pump and the aluminum (although the bottle you have specially calls out protecting aluminum so that part might not be as true) and cause build up problems. What color is the coolant you have in there now? If it's red use Toyota red or one of the bottles at the auto parts store that says "for asian vehicles". Those contain no silicate and have phosphates added. If it's your more standard green/yellowish color then, assuming the previous owner did not use the old silicate stuff, look for the stuff that says "for all makes and models". The reason it says "for all makes and models" is because it does NOT contain silicate so it won't cause those kinds of issues, at least enough so for the manufacturer to claim "for all makes and models" without worrying about getting sued.

I've used the NAPA extended life all makes and models coolant for over 10 years in the car without any issues. Just did a coolant flush recently and the passages that I could see looked fine and nothing crazy looking was floating around in the coolant when I drained it. I ended up using the Prestone all makes and models one since it's easier to source out here and it was on sale :)

I went down the same rabbit hole when I did my flush since the TSRM/manual basically just says "use good ethylene/glycol based coolant". I finally settled on just using the normal parts store stuff instead of going to the dealer since I've been using the normal stuff for so long already and basically self-tested it in the car for the past 10+ years as being safe to use.
 

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The conventional forum wisdom has been to use the Toyota red coolant due to the formulation supposedly having been tailored/known to be compatible with the aluminum alloys in the 7M.

Are there others that can be used? Probably. Do i know what they are? No.
 

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Not just aluminum, as that's in every car these days, but because of brass which is still in lots of the mk3 fittings and the original radiator had a brass header tank and ferrous from the block. Asian manufactureres specify silicate free antifreeze which green is not. I personally always use Toyota red which was the factory fill.
 

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Toyota Coolant isn't that expensive. Just use Toyota Red.
 

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Toyota Coolant isn't that expensive. Just use Toyota Red.
Totally agree - I'm not sure why people tend to veer away from the Toyota stuff. If your local dealer has an online parts sales arm or will price match the online places, you can get a few % off which helps. But as above, it's not that expensive and it works.

Also, conventional wisdom says don't mix coolant types (i.e. colors).
 
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