Well, given the large volume of coolant in the SRT-6 between the Cooling system and Intercooler system, I added one whole bottle of Redline Water Wetter to it as I do with all my cars. I saw no difference either. The gauge still read just over half way. So I did some math and decided that another bottle of the stuff couldn't hurt. Now given that the Water Wetter is Red/Pink, and our coolant is blue I expected it to change the color slightly with two bottles. Well it didn't. The coolant looked the same. And with two bottles the gauge reads slightly below half way while the car is moving. Did the trick and have no adverse effect that I can see... These things have A LOT of coolant and can take two bottles.