First and foremost is your engine. And today in this video we are referencing the Rotax 912 engine. Most piston engines including the Rotax 912 have a overhaul of 2000 - 2500 hours.
You change the oil in the Rotax every 25-50 hours depending on the grade of fuel you’re using. Great thing about Rotax engines is that you can use Mogas (car gas) to run them, and you’ll save money not only on fuel cost but also on your oil change.
It just so happens that car gas leaves less led deposits which means you can run the oil for up to 50 hours before changing your oil and filter.
If you’re using 100 LL which is the standard fuel for most piston engine aircraft, then you change the oil every 25 hours. More maintenance checks need to be done. Watch the video for full details.