best coolant type to use...
 

Hey, I've got a S3 Rx7 with a 13Bbp & efi. What is the best type of coolant to use, premixed or concentrated?

concentrated with 10% water wetter and 30% water, premix urself

Most coolants work ok but something that is aluminum compatible is better for the rotary. Don't buy the cheapest shit out there ,Concentrated around a 50-50 mix with good clean water ( distilled would be great that way there are very low trace elements that can cause corrosion , salts and calcium are very bad for any cooling system ) after all it's not like you need to put it in every day == I hope . :)

^ I definitely agree with distilled water. +1


I don't think so. Only 30% water??...

Plus, I've heard mixed reviews about using coolant additives in rotaries.

Depending on your climate, I used to run water with the Red Line additive.

The climate should not have a lot to do with the mixture .. Anti freeze is also a anti boil product .. A 50 50 mix is all that is required ( a too strong of mixture will have the opposite effect and could jell up when cold )down to about -40 f and will change the boiling point from 212 f to around 230 -240 f .. I don't believe in additives but if you want to add something add a good quality water pump lubricant.:) .

But water has better heat transfer. :)

Distilled water and water wetter, if it doesn't get too cold where you live.

Green, NOT orange colored antifreeze. And whatever you do, don't mix the two.

Which is sharper a knife or a knife

A 50/50 mix isn't always needed. The boiling point of water in a cooling system is raised by the coolant and the fact that the fluid is under pressure. In fact, for most climates (over 3* F), Mazda even recommends a 65/35 split, water to coolant (this is per the 1991 FSM, I imagine other years were very similar). Always use green coolant in a rotary, as previously mentioned.

Plus 1 for more water to coolant ratio, coolant essentially raises your boiling point of the fluid, but if your fluid is getting close to boiling that you need a higher max temp, you have a bigger problem then a mixture of coolant

Why not just follow the manual? It specifies something like a 70/30 mix of water and regular old ethylene glycol. Then for extremely cold climates, it's 50/50.

Done and done, very easy.

In all the posts I see people say to use GREEN. Prestone does not even make a green antifreeze now. They have yellow which I believe replaced the green stuff. They claim their yellow is safe for all cars and can be mixed with anything.
I believe Peak still makes a green.

I dont have a dealership by me to pick up some of theirs and I dont want to order any. Should I get the Prestone yellow or the Peak green?

Because if you do that, then you can't bitch about how your rotary engine is overheating in the 120F heat after you fill it with the 50/50 mix that you read about on teh nternet, you can't complain that your coolant seals are leaking after you fill it with Dex-Cool, and you can't complain about all of the deposits after you use tap water. Life is too boring if you read manuals. Besides, everybody knows that engineers don't know n-e-thing.... especially engineers who tell you to read the manual. ;)

Yellow and green are passe'. Now everybody is using papya whip semi-gloss, although the proletariat are mostly using last year's titian egg shell metal flake.

Have you ever heard of this stuff called evans? Ive never used it but its research worthy.

Evans NPG is great....if you never get too far from home and have a lot of money. It's expensive (~$40 @ gallon last I saw), and you need to purge your cooling system of other fluids. And if you spring a leak anywhere you won't be able to find it at your local Autozone or Walmart. So if you tend to get farther than a taxi ride from your home where the emergency supply is kept, you need to carry it with you...just in case.

Any Ethylene glycol (green stuff) works fine in ratios with distilled water appropriate for the climate. I have NEVER seen it "gel"... never. And it get's damn cold where I live. The biggest thing to remember about coolant is that it's not forever. It gets acidic over time and needs to be changed just like any other fluids in the car. I change mine in the spring when it comes out of storage. Doesn't take too long or cost much.
I've used the Water Wetter products, and NOT used them. Personally I've never noticed any perceptable difference in temps.