In my lower-priced vehicles I have been running RV plumbing antifreeze plus a bottle of antifreeze rejuvenator. I can usually buy it for $4.00 a gallon, it's premixed 50/50 propylene glycol with a corrosion inhibitor.
My local WallyWorld stocks a huge amount every year and clearances it out every Spring. It does have that weird pink color, though.....
