It's time to change the coolant in my 850. Last time I did it, I bought (and paid through the nose for) a gallon of genuine Volvo coolant at my dealer. I was debating whether to use an aftermarket brand this time as I was looking at the empty Volvo coolant container that I still had. Turns out it has an ingredients list:

Ethylene glycol (107-21-1)
Diethylene glycol (111-46-6)
Sebacic acid (111-20-6)
Sodium hydroxide (1310-73-2)
2-Ethyhexanoic acid (149-57-5)
Corrosion inhibitors
Defoamer
Silicates and dyes

If anyone knows of an aftermarket brand that has the same chemical makeup, please let us know.

-dave

I spoke with my Volvo dealer (parts department and service department) as long as the coolant can be used in an aluminum block, it is okay. Just don't mix coolants.

You are just paying for the packaging.

Flush regularly, use coolant formulated for aluminum blocks and you are fine.

Lawren

Any coolant that is "phosherous free" should be okay for the aluminum engine. I saw one coolant labeled "phospherous free, safe for aluminum engines". Can't remember where, but I would think that most auto parts store would carry those.

Dave,
There is no "Secret Formula". Use Prestone, Peak, or whatever is on sale at at your local auto parts store. The "SECRET" is to change it every 2-3 years and to check your hoses so it doesn't leak out.
--
Tom 69-1800S, 72-1800ES, 96-850T

The secret would be in the profit they made.

850 Engine blocks are made of aluminium. If you do not use Volvo coolant, the coolant will react with the aluminium and cause the coolant to turn to a sludgy brown substance which can cause trouble with head gaskets etc...
I have seen this happen with other coolants, for instance "Peak". So yes, it is very important to use Volvo coolant!!!!

I have been using Peak in my 96 850 ever since I bought it in 98. No "brown sludge", ever. Peak is formulated for aluminium blocks, as are all modern day anti-coolants. You are just paying extra for the Volvo packaging.
--
Tom 69-1800S, 72-1800ES, 96-850T

I went through this discussion a couple of years go. Since no clear answer was given, I bought a gallon of Volvo antifreeze from a dealer. It was some $14. I decided that extra $8 every 2-3 years is not that much for peace of mind.