Info:
With Inventor 2018, we focused on three key areas: Professional-Grade Design, Expanded Interoperability and The Inventor Experience:

Professional-Grade Design

As we all know, design tools can never be fast enough – especially when working with large assemblies and drawings. Building on work we have been implementing over the past few releases, Inventor 2018 delivers significant performance improvements for customers who need to open, update and navigate faster within their Inventor assemblies and drawings. Based on feedback from customers during the alpha and beta testing of Inventor 2018, users are seeing speed improvements from 2X-10X on their designs.
We have also seen customer demand for tighter integration between design and manufacturing, as well an industry push toward Model Based Engineering (MBE). We added an entirely new set of functionality in the 2018 version by including integrated Model Based Definition (MBD) as part of every seat. Tolerance features are automatically recognized using an embedded GD&T engine, which allows designers to create fully constrained models. Users will also be able to leverage MBD data for downstream consumption (tolerance analysis, CMM, CAM, etc.). Finally, Inventor 2018 allows for publishing 3D PDF and STEP AP242 of part files with MBD and 3DA information included.