Coolant questions.

While coolant and antifreeze may have some differences in chemical composition, I use the terms interchangeably for the purpose of making this simple to understand.


Green coolant is the normal coolant or antifreeze most of us are used to. We mix it 50/50 with water to raise the boiling point of water from 212F to 240F or so. (See FAQ # 19)


Red coolant is normally the same as green coolant except found in foreign and European cars.


Orange coolant is the long life coolant found in many newer domestic cars and trucks. It is not supposed to be changed for 100 to 150k or 5 years or so.

And today we have maybe 3 other colored coolant!

We process about 10k cars a year and we are seeing a couple of things with the orange long life coolant that makes us very uncomfortable. We are seeing a brown thick milky substance floating on top of the coolant in the overflow jugs and we are seeing an orange like gel (looks like jello) just under the radiator cap and in the neck of some radiators on some cars with long life orange coolant. We are also seeing much more corrosion on newer model cars but we are unsure if it is related to the orange long life coolant or not.

Last, most folks are very uncomfortable leaving the same coolant in their car for 100k. Really, there is no way a car will end up with the same coolant for 100k because we will have to do some cooling system repair (water pump, hoses, radiator) in that first 100k and very few of us will contain and reuse coolant we drained from a customer’s car.

Because the orange long life coolant is much more expensive, this is what I have decided to do with my personal cars. I leave the orange long life coolant in until I have to open the cooling system up or 35k, whichever comes first. Then I flush the cooling system real well and install the cheaper, green coolant.

Until the brown thick milky substance floating on top of the coolant in the overflow jugs and the orange like gel in the radiator necks has been explained, I’m simply more comfortable with the older, proven green coolant.

You may be told that you must use the newer orange long life coolant and that simply is not true. Most all of the engine platforms of today were engines that used the green coolant before the orange long life coolant came out. Besides, if a dealer or manufacturer dictates a certain product ONLY, by law they have to provide it for free (Magnuson - Moss Act).

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