Antifreeze: brands and underlying theory

[erikv11]

The suggestion is simply to flush with water, not to use it instead of a mixture.

E.g. for 10 minutes around town or until the engine gets good and hot in the driveway. Completely inconsequential to the engine's cooling system (unless it helps it, by dissolving precipitates!).

[JaneDoeS40]

Many of the coolants are not compatible with each other. Even the coolants labelled as compatible with anything may not actually do anything harmful but they may take the coolants life from 5 years to 2 years.
Since you have doubts drain it and flush first with tap water. Then get 8 gallons of distilled water. It is a dollar usually at dollar stores and even less at Wal-Mart. Flush it with 6 1/2 gallons of that. Now use the Pentosin and distilled at 50/50 mix. Maybe a little exra antifreeze to compensate for some of the flush distilled that is left behind.

Hey thanks for the advice. I thought about doing it myself, but then I watched a couple YouTube videos and chickened out! Good think I did, though, as the shop told me I need a transmission fluid flush, as well. Had I done the coolant flush myself, I never would have known that.

[rspi]

Can the Valvoline Zerex G-05 be safely mixed with the Volvo blue stuff?

[rspi]

Never mind, I found my answer in post 13, yes I can.

On another note, whomever runs straight water in their cooling system is crazy. Water boils at 212 degrees F. It also doesn't carry anything that would lubricate or prevent rust. A lot of minerals in tap water will also produce sludge in the system. Have fun with that. These cars get over 212 degrees all the time. A boiling motor will increase pressure to the point that hoses, etc. can blow.

Most 50/50 coolant mixes boil at 265 degrees and 275 degrees under pressure, the P80 cars have a pressurized system.

[rmmagow]

So, is G-05 the equivalent of the Volvo branded fluids? I.E. HOAT?

[JimBee]

After a thorough discussion of this topic, here, a couple of years ago, the consensus was Zerex GO-5 is the way to go. That's what I've been using in 2 850's.

[rspi]

So, is G-05 the equivalent of the Volvo branded fluids? I.E. HOAT?

Yes...

[eomutlu63]

Is Valvoline Zeex G-05 only HOAT technology coolant in the aftermarket?

[eomutlu63]

Well - there is a problem with that. Its localized boiling. If you have a non turbo car then you can use the regular prestone. (See update below)Prestone is an OAT technology (Organic acid technology) coolant. A Hybrid OAT (a mix of oat and other ingredients )is called a HOAT- Hybrid OAT. A HOAT is used in modern diesel engines and other turbos as well as all BMW and Mercedes. (Did you ever notice that BMW coolant and Volvo coolant are exactly the same). Volvo HOAT contains Sebacic acid and some silicates on top of the normal OAT ingredient of 2 -EHA . These are the chemicals that make a difference o keeping it from boiling over and repairing damage to aluminum at a molecular level.

HOAT does much better job at not boiling over quickly at the cylinder walls when the heat increases suddenly (during turbo boost). An OAT does not do as well and depending on how hard you run your turbo,you can create enough localized boiling (with an OAT) to overheat the head which will lift at the centerline and produce cylinder walls crack across the centerline of the motor.

If you have a turbo please use a HOAT antifreeze.
On all cars please use premix 50/50 (can not be had from Volvo) or use mineral free or distilled water when mixing your 50/50.

2011 - many producers of antifreeze now warn that mixing an OAT wit a HOAT can cause gasket problems including early failure. I suggest only using a HOAT for Volvo applications

[cn90]

Independent of all these HOAT debate, I have been using Prestone green coolant in many many cars for the last 25-30 years, replace the coolant every 3y or so.
Zero issues.