[Greg83]

I know this has been discussed but I can’t find a GOOD answer. I know most guys use 10-4034 dif fluid in there ZL1 but that doesn’t seem to be synthetic. I just left my dealer and after using my vin to look up the correct fluid they recommend using the synthetic 10-4016 and adding the friction modifier. He seemed to think you pore in 1 friction modifier and then fill the dif with the synthetic 10-4016 until it’s full. What are you guys using and if using the synthetic 10-4016, are you just adding the one 4oz bottle? Thanks!!