Antifreeze: brands and underlying theory

BIG DOG · Post by **BIG DOG** » 14 Nov 2009, 15:02

I have read a few post and they say to use volvo recommended coolant.I have alway used prestone in everything that I have run it suppose to be good with all aluminium engine parts and I have always had good luck with it.Is there any reason why it can't be used in our engines?
Thanks!

Japedo · Post by **Japedo** » 14 Nov 2009, 15:05

I've used prestone on my volvo's, bottle says approved for aluminum engines. Have never had any troubles.
I'm in New Brunswick myself.

Curtis
94 850 turbo 491kms
01 V70 XC 240kms

Post by **JDS60R** » 14 Nov 2009, 15:25

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

Japedo · Post by **Japedo** » 14 Nov 2009, 16:02

My turbo 850 likes the coolant I run. I mix it prestone 50/50 with water from my tap. Also as the boost increased with a boost controller. No boiling noted.
Maybe the climate u drive your car in might dictate what coolant you use. The more expensive products always have "good" reasons why the cheaper products are inadequate.
I actually installe d anew rad this summer in my car and didn't have any coolant on hand, ran straight tap water in it all summer, just changed it about a month ago with the colder temperatures.
THis is just my 2 cents tho.

94 850 turbo 491kms
01 V70 XC 240kms

Curtis

voodoorobaz · Post by **voodoorobaz** » 14 Nov 2009, 16:20

I live in Arizona and I use prestone on my v70 xc which is a turbo, Never boiled over or anything like that. Seems just fine. I flush it every 2 years also. I wouldn't go with a cheap brand like coastal. I also us tap water for the 50/50 mix. Sometimes I go with a 70/30 mix for the summers here in Arizona. 70 being the coolant itself.

Post by **polskamafia mjl** » 14 Nov 2009, 17:22

voodoorobaz wrote:I live in Arizona and I use prestone on my v70 xc which is a turbo, Never boiled over or anything like that. Seems just fine. I flush it every 2 years also. I wouldn't go with a cheap brand like coastal. I also us tap water for the 50/50 mix. Sometimes I go with a 70/30 mix for the summers here in Arizona. 70 being the coolant itself.

Voodoorobaz, I was just wondering why you do 70/30 in the summer? 70/30 is a suggested ratio for winter when it's cold becasue the 70% antifreeze helps prevent the water from freezing. Like Japedo said, in the summer when it's warm you can run straight water because it won't freeze but it may boil over. 50/50 makes sense for the summer because the 50% anti freeze prevents the 50% water from boiling over...

voodoorobaz · Post by **voodoorobaz** » 14 Nov 2009, 17:34

With a 50-50 mix of coolant and water, the Prestone Extended Life Antifreeze/Coolant is good from -34°F all the way up to 265°F. With a 70-30 mix, the antifreeze/coolant is effective from -84°F to 276°F — sufficient for almost any inhabited locale in North America.
Actually, this is to be expected when one considers that ethylene glycol, the principal component of most antifreezes, freezes at 8 degrees above zero, Fahrenheit. It is only when water is added that the freezing point is depressed. The freezing point of an ethylene glycol and water mixture drops rapidly as the concentration of glycol is increased to a mixture of about 60% antifreeze and 40% water. Around that point, an abrupt turnabout occurs, and as more antifreeze is added, the freezing point rises almost as fast as it had previously dropped.
Fine with 50/50 mix really but with 70/30 I don't have any leftover coolant to lay around my garage. Straight antifreeze in a big no-no.

Post by **polskamafia mjl** » 14 Nov 2009, 21:00

Good information to know, thanks a lot.

Post by **stone36** » 24 Sep 2010, 09:38

I need to add some AF to my xc90 2.5T. Can any "HOAT" premixed 50/50 work? Volvo also has the warning on the reservoir about not mixing different types of Anti Freeze as well.

rangema · Post by **rangema** » 24 Sep 2010, 11:40

Tap water is ok if there are no minerals in it. Have you tested your tap water for mineral content? Me neither, so I use distilled water because of the various minerals in my tap water like iron etc.
98 S70
280,000 km