Increased oil consumption at ~65K miles?

Quicksilvers

If you are using a good quality synthetic motor oil you will not need to use an additive in your motor oil and I would advise against using any motor oil additives. You should lessen your mileage on your oil change intervals and begin using a thicker weight motor oil. Although a bandaid and not fixing the oil consumption issue it will help the motor oil consumption issue slightly. Unless you are using the wrong weight motor oil you will never really know the root of your oil consumption issue unless you began a engine tear down. Having known several people how owned Mazda RX8’s they have a much worse motor oil burning/motor oil consumption issue than the Nissan 370Z ever did. You are fortunate that you replaced your oil galley gaskets when you did it more than likely would have costed you an engine. I don’t ever remember any of the Z’s I have ever owned to start consuming motor oil. You can start using Mobil 1 5W40 Euro I have seen that it will help slightly try it next oil change.

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Mr. Clean