CLRH2O

So today was supposed to be the day (FINALLY) for doing a full cooling system flush, radiator replacement and coolant refill. I'm flushing the green that came in the car when I bought it used from the Mercedes dealership last oct and replacing with the Toyota Red.

Now after MUCH searching, I've found so many different conflicting reports about how much of this, and if you should that and the other together or not... Lexus says "Cant go wrong with 3 gallons of our premixed Toyota Red for a complete system refill including the heater core".... but even @ Toyota your talking 19 bucks a gallon (and 27 per @ lexus).

Then, as an example also echoed in multiple threads here on the forums there was www.lexls.com (which in general is a great site) who suggests only 1 gallon of premixed/pre-diluted Toyota Red and then around 2 gallons of grocery store bought steam distilled for the rest....?!

What EXACTLY is the right way here? What is the total gallon or quart capacity of the SC400 (1991 to 1996 year) cooling system including the heater core?

I think it might also be good info to give that I'm located in Tampa, FL and that it NEVER freezes here...or if it does freeze I guess it's like half of one night every half decade. So that said, would my amount of RED to Distilled be different? I know that water alone cools better (and that's certainly what I want, better cooling) and it get WAY hot here in the summer which is about 8 months of year.

It's already 1:45pm and I was hoping to get this done today but I'm not doing anything until I know what's right and what's not. I'd be greatly thankful for all your help on these (seemingly) simple questions

XxSC400xX

iTrader: (1)

I'm not entirely sure what the capacity on a stock SC400 radiator is, but when I installed my Koyo radiator it took a little over 3 gallons to fill it up. I used about half a gallon Toyota red mixed with steam distilled water and water wetter. Not worried about freezing because my SC is never getting anywhere near ice/snow. In colder conditions use the whole gallon.

CLRH2O

I found that the stock system is 11.8 Quarts which is just shy of 3 gallons.

I'm located in Tampa FL and 50f is about as cold as ever gets down here. I'm running pretty much what you are in terms of ratio. Needless to say, I got the work done yesterday

lxsdude

That is not correct. Coolant has a higher boiling point and prevents your system from boiling over. It also helps prevent against corrosion.

Looking at your more recent post I see that you have completed your radiator work. Hopefully you didn't just fill your system with water alone.

MDeezy

very true. Running just water can boil off quicker than you think, espeically once the sumer temps kick in.

craaaazzy

iTrader: (4)

i ran 25/75 ratio coolant/water in my M3 in atlanta. the thing is, water does have a lower boiling point but it also cools much faster than coolant. so if sitting in traffic a lot, i would do 50/50, but if always moving 25/75 is fine (run at least some coolant for corrosion as stated above).