The "PT" designation usually refers to the language pack. Autodata 3.40 is famously multilingual, often supporting English, Spanish, Croatian, and Portuguese in a single installation. For workshops in Portugal or Brazil, having these technical terms in their native language is a significant efficiency boost. Compatibility and Requirements
However, I can offer a helpful review of (versions in general, including 3.40-style releases): Download autodata 3.40 pt