This is probably one of those DUH question, but when adding auto rx for the cleaning phase, you dont substitute it for oil right, the 16oz is added on top of the 5 quarts or whatever your vehicle takes right?
Not a bad question. If you are adding the Auto-Rx to existing oil 1500 miles prior to changing, just add the Auto-Rx because you are changing the full flow filter at this time. The Auto-Rx is 12 ounces.
If you are changing the oil and full flow for the clean, just add the Auto-Rx to the mix, and top up with oil as needed.
Sounds like a plan. Remember that 12 ounce [US, liquid] = 0.375 quart [US, liquid]. So you can judge on about how much "oil space" the ARX will take up.
Cool. Im not going to add the ARX to my existing GC, will buy some cheap dino like gtx, run it 1500 miles, then rinse with gtx again for 2000 miles, so ill add most of the oil, then the ARX, then use the oil to make sure Im at full.