Richard,

I'm not sure just what the make up of Volvo coolant might be ... but I have used Dexcool, sometimes refered to as the "orange stuff", in all my bricks for years. I've run it in my 86 245DL for four years ... with no problems. In fact I've not had the kind of water pump failures I used to get when using a dissovled solids coolant like stand Prestone. Used to have the seals on the pump go out every 50k like clock work. I've had nothing but good luck using Dex ... in fact just replace the coolant in my 87 745T project car as one of the first steps toward bringing back to life. I don't think you'd go wrong with Dexcool ... just flush your system well before installing it. I mix my coolant 50/50 using Dex and distilled water. The tap water here is loaded with mineral. My$.02