Originally Posted By: Gebo
Originally Posted By: Eddie
The issue with Pre-diluted 50/50 is that about a quart or more remains in the engine when doing a flush & refill. You end up with something like 45/55 when using pre-diluted.
Now that's what I'm talking about...I was wondering if anyone else ever thought about this.....
Sure thought about it. However if doing a simple radiator d&f assuming the preferred 50% concentration has been used all along, 50/50 premix in radiator keeps the system same.
If one wants to do a complete flush/exchange using a premix after a distilled water flush series, then it can become an issue. Have to test the AF concentration (hydrometer), to make sure it's preferred 50% concentration. Depending on how it's done using a premix, can be a wasteful process.
That's why including not paying for half water with a premix, using a concentrated AF is always preferable. Can make your own 50/50 mix for rad d&f. Or, after a distilled flush series, use/fill half system capacity full strength AF, top with distilled water.
To answer question, 50% AF protects to -34F, plenty of leeway most of the US. So 50% AF concentration works for me.