QUICK TEST: PURPLE ICE
The one good thing about HRM’s project cars is that if we need to test a product that claims to fix a particular problem, the chances are that one of these cars has the problem. For example: Royal Purple’s Purple Ice radiator additive is supposed to bring engine temperatures down. Freiburger’s 1967 Chevy® Impala with a 383 small-block gets hot in traffic. Some people in the office were skeptical of cooling additives, no matter the brand. Our testing was conducted on two consecutive days with 68° F weather, running the car with and without the additive. We let the Impala idle for 7 minutes, drove it for 7 minutes and then left it idling facing a garage door (to block wind into the radiator). We recorded the time and temperature each time.
With water only (no antifreeze), the coolant temperature reached 220° F in 41 minutes. With Purple Ice, the temperature reached 210° F at the same time it took water only. Even after 56 minutes of running and then under a strong load, it did not exceed 210° F.
In lower-temperature driving, there was no major difference. Purple Ice is not made to mend a faulty cooling system but to fix minor problems. It seems like it would help if caught in bad traffic.
Purple Ice also acts as a corrosion inhibitor, which is great for those racetracks that allow an additive but not antifreeze. Instructions call for one ounce per quart of antifreeze or one bottle per system (double dosage if it’s water only). We used just shy of two bottles.
