As mentioned above, the base oil doesn’t wear out if it’s synthetic. The additive package does get consumed. How quickly it gets used depends on way too many factors to say there is any relationship between miles driven and oil change needs. The only way to know for sure in any application is to send an oil sample in at an arbitrary mileage to start with, like 3k miles and have it analyzed. Once you get the results you can see what’s left of the additive package, plus other details like fuel and coolant dilution and any bearing materiel and such. That’s the only way to know how often you should change your oil. Of course the oil that is used will also be a big factor in how often the oil needs changed. Some oils use the bare minimum additive package to make the grade.
