This is certainly true. Part of the problem with dexcool is the manufacturers recommend using it for extended periods without flushing.

But also it turns to sludge and/or crust when exposed to air.

So, as long as your cooling system is working perfectly and you change it every 2 to 3 years, dexcool is ok.

But if you develop a leak, expect sludge. If you leave it in too long, expect sludge.

Seriously - why would anyone use dexcool? Does it have some positive aspect I haven't heard of?

 

Supposedly its more "environmentally friendly", which is why manufacturers started using it. All my vehicles run either peak or the conventional green coolant.