Is Prestone “All Makes/All Models” coolant *really* compatible with all models?

Question

My car's manual says to use the blue Honda coolant:

Always use Honda All Season Antifreeze/Coolant Type 2 [MSDS]. This coolant is pre-mixed with 50 percent antifreeze and 50 percent water. It does not require any additional mixing. If it is not available, you may use another major-brand non-silicate coolant as a temporary replacement. Make sure it is a high-quality coolant recommended for aluminum engines. However, continued use of any non- Honda coolant can result in corrosion, causing the cooling system to malfunction or fail. Have the cooling system flushed and refilled with Honda antifreeze/ coolant as soon as possible.

On the other hand, Prestone claims their green coolant is harmless:

Prestone® Extended Life Antifreeze/Coolant is compatible with ANY antifreeze/ coolant – regardless of color – for use in ALL makes and models of cars and light duty trucks. This patented formula provides a high degree of performance durability and carefully balanced protection against temperature extremes and rust corrosion of all cooling system metals, including aluminum.

Who should I believe? Will it really result in corrosion if used more than temporarily?

Answer 1

Every manufacturer recommends their own fluids. Everybody wins because your engine gets "less corrosion" and they great great markup on those things.

A while ago I did cooling system maintenance (replace hoses, water pump, thermostat, temp sensor, radiator cap) on my wife's BMW 330i. That make/model has a lot of following and several high-quality forums with lots of people and lots of opinions. Half the people on those forums are under the impression that if the fluid doesn't have BMW written on the can, it can't touch the car. The other half (equally knowledgeable and competent people) is using Prestone. I have not read any post that suggested Prestone caused any kind of problems.

That's what I've been using in all my cars, including the BMW, and I never had any cooling system problems either. I sold my Integra with 194k and engine was still fine. Rust ate away a lot of the body.

Answer 2

I don't know if it is the same in the states, but over here there are two totally incompatible types of coolant - OAT (usually red) and MEG (usually blue). Using the wrong sort can cause corrosion issues and leaks (especially using OAT in a car designed for MEG), and mixing the two results in a rather nasty sludge. However, most cars in the past decade or so have used OAT.

I can't therefore see how they can sell a coolant that claims to be compatible with ALL cars, unless things have been different over there?

Another thing to watch out for is that if your car is still under warranty, they may refuse to pay out if you have a leak and have used a non-approved fluid in the car.

I personally tend to use whichever brand my local motor-factor has in stock at the time, but always make sure it is the right type - but then all of my cars have been fairly old, and from before manufacturers started trying to insist that you used their own brand coolant!

Answer 3

From FAQ section of Prestone Website:

"Some European automobile manufacturers request that a phosphate-free antifreeze be used in their vehicles. This issue is related to the extremely high mineral content of the water in Europe. If you were to mix an antifreeze that contained phosphates with the type of water they have in Europe, it may produce deposits that can settle in the cooling system and promote corrosion. However, in North America we do not have this type of water problem. Typical North American coolants have contained phosphates (which is part of the corrosion inhibitor package) for many years. Therefore, the question of phosphates is a non-issue here in North America. Prestone® Antifreeze/Coolant is completely safe for use in both foreign and domestic vehicles. For those consumers who would feel more comfortable using a phosphate-free antifreeze, our Prestone® LongLife® Premixed Antifreeze/Coolant and Prestone® Dex-Cool® Premixed LongLife® Antifreeze/ Coolant formula’s are phosphate, silicate, and borate free. These coolants use a special chemistry and technology that extends the life of the corrosion inhibitor package so that it lasts for five years or 240,000 kms (whichever comes first), and is safe for all cars and light trucks (old or new). Prestone® Dex-Cool® Premixed LongLife® Antifreeze/ Coolant has been approved by General Motors under their DEX-COOL® specifications and is compatible with other DEX-COOL® approved coolants. * DEX-COOL® is a registered trademark of General Motors Corporation."