Use dexron 4 by itself. It is the better fluid.hey king nice write up very informative. i have a question for you. the stock fluid is dexron III is it safe to mix III and VI? i was told that was a no no. my fluid is a slight pink color at 121xxx miles. idk if the filter has been changed or if any other transmission maintenance was been done. my car was a cop car out of chicago until i bough it at 88xxx miles. 2003 3.8. what do you think?