Lawrence: Go to No-Rosion's website. They have a lot about which antifreeze to use and why. If the car is pre-1993, stay with the old Conventional antifreeze. There are major chemical reasons to NOT use Long-Life coolants in pre-1993 cars. Also depending upon where you live, the lower concentration of antifreeze the better. No-Rosion is the real deal and they have a lot of knowledge on this subject.
I have run Evans NPG in my older cars and highly recommend it. No issues in 15+ years. No water means reduced corrosion issues and you do not need to change it frequently. Because the boiling point is so high there is less stress on water pump seals, hoses, head gaskets, etc. I once took my Countach for a long drive and left my radiator cap on the bench in the garage without issue.
Again, for what it's worth, if anything, but in past 40+ years and half a million or so driven miles with hundreds of 50-100 y.o. vintage cars, I've been using conventional anti-freeze coolant, mixing it myself to +/- 50% , and haven't experienced reasons to change nor been convinced by marketing efforts of any Johnny-come-lately brands. OTOH, unlike probably vast majority of vintage car owners or mechanics, I do clean/flush/service entire coolant systems on (vintage) cars as a part of regular maintenance. Same with brake and fuel systems. Based on my observations, most owners don't give any of these "systems" a second thought until there's a problem, sometimes a major, but which often could've easily been prevented with properly scheduled maintenance.
