The Continental IO-550 engine is a large family of fuel injected six-cylinder, horizontally opposed, air-cooled aircraft engines that were developed for use in light aircraft by Teledyne Continental Motors. The first IO-550 was delivered in 1983 and the type remains in production.
The IOF-550 is an Aerosance FADEC equipped version of the same basic engine, the TSIO-550 is a dual turbocharged version and the TSIOL-550 is a liquid-cooled variant.
There is no O-550 engine, which would be a carburetor-equipped variant, hence the base model is the IO-550.
This engine family competes with the Lycoming IO-580 series which are also six-cylinder engines with similar power output and weight.
Read more about Continental IO-550: Design and Development, Variants, Applications, See Also