File size dramatically increases & slow opening/plotting - C3D 2014

I'm using Civil3D 2014 (DWG version 2013) for most of my files. My firm has been having problems with our files in that any time we save in this program or format our files bloat to 2-5MB and stay there. It's typically a one-time occurrence when the file size jumps like this, but it will stay at this size unless we export to 2010 DWG and use the file through regular AutoCAD 2014. The problem with these large file sizes is that it slows down opening and plotting time tremendously (up to 20 minutes waiting for a single file to open).

I've searched through tons of forums and have tried the following:

ISAVEPERCENT=0 (already set to this)

-PURGE REGAPPS (yes, keeps file clean)

PURGE (yes, keeps file clean)

AUDIT (yes, keeps file clean)

INDEXCTL=3 (yes, helps a small amount)

DEMANDLOAD=3 (yes, helps a small amount)

XLOADCTL=2 (yes, helps a small amount)

TREEDEPTH=32767 (yes, helps a small amount)

TREEMAX=10000000 (yes, helps a small amount)

EXPORTTOAUTOCAD (no, explodes C3D objects and exports)

SAVEFIDELITY (for use with ACAD 2007 and earlier)

WHIPTHREAD=3 (no noticable effect; allows for multiprocessor use for rendering/redrawing)

PROXYGRAPHICS=0 (makes file size increase and doesn't allow graphics in regular AutoCAD)

MAPCLEAN (no noticable effect; allows for deletion of "hidden" objects and simplifies complex linework)

SCALELISTEDIT (no noticable effect; allows deletion of unused scales)

OPTIONS/OPEN AND SAVE/FILE SAVE: uncheck "Maintain visual fidelity for annotative objects" and "Maintain drawing size compatibility" (no noticable effect)

THUMBSIZE=0 (no noticable effect; thumbnail picture quality)

AUTOCAD DGN HOTFIX FOR 2013/2014: DGNPURGE command is not recognized, even after "unblocking" it per instructions

I have ruled out a corrupt template as a potential cause because I started a new drawing from no template and the blank file saves to a 2MB file (with it being totally empty).

Does anyone have any knowledge on what I could do to fix this? This isn't a single computer station that this happens on, it's out entire office. We've tried reinstalling Civil3D and have even replaced a couple machines recently and this file bloat continues to happen. Any advice is appreciated!

Audit is used to fix database errors.

I don't see Overkill mentioned.

Upload the drawing to a file sharing website a post a link to it here. Someone will take a look at it and perhaps come up with an answer.

You simply need the fix released in ±Aug 2016 for C3D.

Install the fix on ALL machines that will touch/save your DWG files.

The effects of the fix will not be witnessed until after you save the file (and all xrefs and data shortcut ref files) and then you'll see the effect when you open then the NEXT time.

If an unpatched machine saves a file, the data bloat will be added back to the DWG file.

I don't think OVERKILL is the solution since the problem is happening in a totally blank file too.

I would post a file, but rkmcswain has provided the answer. I did the Civil3D performance enhancement and about 1.7MB is dropping from my files at save. It still takes a long time to open files with lots of C3D objects (12min+/- instead of 20min), but the ones that contain mostly 2D linework are opening in less than a minute now (from 5-7min).

Thanks for the help!!