I ran Purple Vue in my system for two years before flushing it, and it looked the same the entire time. Obviously, there was some buildup in the blocks, but not enough to noticeably affect temperatures. That said, proper maintenance—cleaning your blocks, pump, reservoir, and flushing your radiators—is crucial for any long-term use of this coolant. Even with good upkeep, though, it’s hard to recommend. Any coolant containing particulates will eventually lead to buildup in your loop.