Originally Posted by Bronxie
I thought rotaries last longer because they have only 3 moving components in the engine.
Just because there are only three major moving parts doesn't mean that the ancillary bits don't wear out. The seals on the rotors are a major wear area, and lack of proper oiling, or overheating, can cause major issues. They don't like detonation at all, and one little ping can ruin an engine. Once you start making real power with them, the reliability goes out the window, as well. Stock, normally aspirated rotaries have been known to go over 250k miles with proper maintenance. Modded ones barely last at all.
My stock one died at 100k, but I don't know how it was treated before I got it. Since I had done a lot of rotaries in my day, I decided to do something different and swapped in a light V8.