Marty, your experience pretty much mirrors my own with Dex-Cool - two '86 "Mitsubishi" Precises (bolt-for-bolt, a Hyundai Excel), an '89 Toyota truck (22R), and a '96 Honda Accord (I-4). Nary a problem with any of 'em and the radiator cores remained as clean as the proverbial whistle with Dex-Cool and tap water. My current driver is a 2003 Hyundai Sonata (V-6). Hyundai gives no specifics about the brand of antifreeze/coolant concentrate to use, and as far as I'm aware, there isn't a Hyundai-branded antifreeze/coolant available in the U.S. either. The owner's manual merely advises to use "a high quality ethylene-glycol coolant in a 50/50 mix with water. The engine coolant should be compatible with aluminum engine parts." My crystal ball suggests my Hyundai's cooling system is gonna see Dex-Cool, too (since I already have 3 gallons of the stuff on hand...), though I've laid in 12 gallons of "Wal-Mart's finest" 58 cent distilled water for a thorough mineral-free flush before introducing Dex-Cool into the car's cooling system. Perhaps someone who feels qualified can answer a question which continues nagging me in the ongoing Dex-Cool saga: if Dex-Cool is such a villain, how come the horror stories seem to center most often on certain GM pushrod V-6 and V8 motors - which had known issues with new technology cylinder head and intake manifold gaskets that allowed outward coolant seepage when hot, and sucking air during the cool-down phase? While of no immediate concern, over time, enough air is introduced that, even at running temps, certain internal components were no longer immersed in and protected by the corrosion inhibitors.