This is from the Peak FAQ.


Why does my vehicle owner's manual recommend a phosphate free antifreeze?
Some European car manufacturers recommend that phosphate free antifreeze be used in their vehicles. The reason is that the water in Europe has an extremely high mineral content. If you mixed an antifreeze containing phosphates, which are part of the corrosion inhibitor package, with the water they have in Europe, the phosphates in the antifreeze may "drop out" and form deposits in your cooling system that can lead to overheating and corrosion. However, this is not a major concern in North America, since our water is lower in mineral content, or softer, than European water. If you are interested in a phosphate-free antifreeze, Old World Industries offers PEAK™ Global LifeTime™ Antifreeze, PEAK Long Life Antifreeze, and SIERRA®, the Safer Antifreeze.

 

I stopped in the dealership today while in the big city and had the parts guy quote a 4L jug of coolant. With the PCA discount their price was reasonable enough that I bought it.

Thx for all the discussion.