W -
>> I know this is a much debated topic...
Much!
In fact, I finally decided to stop listening to all of the "experts" and research this one myself. Here are a couple of highlights (of many, boring details...)
1. Color has no bearing on the formulation. The manufacturers add color for distinction, for marketing, and perhaps because of the phase of the moon;
2. The additives in each type are usually different, and therein lies one of the major problems, or solutions to coolant issues;
3. Mix different additives, as Beo says, and they can (and often will) precipitate out of solution into various forms of pooky and grungus that will play havoc with the cooling system over time;
4. The Toyota (so called, "Red") has NO borates, and very little silicates... and in that respect, differs considerably from some of the others (yellow, green, etc). Just how much this matters is what forms the basis of the great debate;
5. If you subscribe to the theory that Toyota engineers know what they're doing, then you will probably opt for the Toyota Red;
6. Whichever you use, be sure to do a really thorogh flush, not just a simple draining, use only distilled water... and the general wisdom of the sages is to NOT use the organic acid technology (OAT) types of coolant, since 1FZ-FE was not designed for it.
Cheers!
R -