For some reason, 500 miles comes to mind.
Also recently read a white paper on synthetic oils out of the EU. Basically it says all the synthetics they tested were good for 7,500 km (4700 miles). After that the additives started depleting.
If I can find the link to the white paper I'll post it.
Nowadays, a car’s engine oil change interval is an essential factor in reducing wear. The correct choice depends on various factors. This study analyzes the changes in the composition of three different engine oils (0W30, 5W30, and 5W40) during the generally accepted oil change interval (15,000...
www.mdpi.com