Ron Wanttaja wrote:

One reason: They don't like 100LL. They're approved (and certified) to operate
on it, but the lead forms an abrasive sludge that means the oil has to be
changed more frequently.

Not that big of a deal with a private owner, but an FBO won't like having to
take a rental off the line twice as often to change the oil.

The Rotax specified oil change interval if you run unleaded is 100
hours. If you use 100LL, it is 50 hours.

They're reasonably specific about what type of oil to use though - the
best seems to be semi-synthetic motorcycle oil. Full synthetic is also
a no-no if you're using 100LL.

What is the typical oil change interval for a Lycoming or Continental?
--
Andrew Rowley