[BirdDog]

Just want to throw in here that the official Porsche coolant (the pink stuff) isn't all that expensive - It's something like $42 a gallon from the dealer, but that makes 2 gallons of 50/50 mix, so $21/gallon of 50/50 mix, which is pretty close to what the Prestone long-life 50/50 costs at your local auto parts store. And remember to ask you Porsche parts guy for a club discount (my dealer offers one) if you're a PCA member.

I'd caution that whatever you do, don't mix coolants! if you switch to something that isn't already in there, be sure to do a thorough flush before refilling with fresh 50/50 coolant. Mixing different coolants can result in the formation of a gel like glop which can cause overheating from restricted coolant flow.

Also, if you go with the Porsche coolant, be sure to use distilled water (not tap water) when cutting it to 50/50.

If you're on a tight budget and your current coolant is fairly new, if you can catch it in a CLEAN basin, I don't see any harm in reusing it as long as you pour it back in filtered (through cheese cloth, an old bed sheet, etc).