Is there any reason to suspect ATF manufacturers (in this case, Conoco) have changed their DEXRON III?
It can't hurt to swap the Super ATF for some DEXRON-VI, but I wouldn't worry about what you've got.
Is there any reason to suspect ATF manufacturers (in this case, Conoco) have changed their DEXRON III?Yup. The only reason I say to get 6 is because GM no longer licences 3 and it might not be exactly what they say it is.
This is true of your car. DEXRON-III was the factory fill for your car, and if you read the Owner's Manual, I'm sure that's what it tells you to use.The bottle says "recommended for use in all domestic and import vehicles no longer under warranty where the OEM previously specified a GM DEXRON III or earlier generation DEXRON fluid"
For you, it means nothing. DEXRON-VI didn't exist until 2005, so your 2004 could not possibly have required it.It later says "do not use in automatic transmissions that require a GM DEXRON VI" and a couple other of fluids by ford. So what does this mean?
There may be some mileage benefits (that was one of the purposes of GM changing from DEXRON-III to DEXRON-VI). Whether that benefit will actually be measurable, I have no idea. There's absolutely nothing wrong with using either DEXRON-III or DEXRON-VI in your transmission; whether the VI is "worth it" is up to you.Is it worth it to spend the extra money and go buy some DEXRON VI?