I've had blurry ground textures for about a year now. I'm not sure what is causing them. When I start my flight the textures are generally good but by the time I get to my destination they are blurry. See attached image of the blurriness levels. This happens with any plane at any location. 

This affected by fiber frame fraction and (to a lesser extent) texture bandwith multi in the cfg file. Try raising your fiber frame fraction and see what happens.

I've tried raiseing it from .33 to .50 to 1.33 to 4 no differance

This is cause level of detail is too high to maintain the selected fps. Try fiber frame to 0.01 tesselation factor high, distance medium,scenery complex and building normal, switch water to off and shadows to low. It was a headhache for me and it was the solution. Fps unlimited of course.

I had this when using Fiber Accelerator.  Reduced the frame rates and it went away.  So I think they are right.  Lower frames or changing the Fiber frame faction would be where I would start.

Attention! My personal experience is, that the blurry Textures are mostly a result of frequently Installing and Deinstalling Addon and Freeware Sceneries! (Be careful also if you deinstall e.g. UTX or other Area Sceneries)

 

Essential FSX-Files are gone or left Overwritten. Most critical are Entries in the Autogen Description or Terrain.cfg-Folder - and of course all Scenery and Texture Files!

 

The more Sceneries you install - and deinstall, the more Danger comes on, that your Base-FSX-World is going confused!!

 

To avoid all that for me, i took another FSX-Install on a seperate PC and let the Installers do there Work into my created Dummy Folders. So i can see what happens- and afterwards, i copy the depending Files manually to my main FSX Machine!

 

A lot of Work, sure, .. but the earnings are a sharp and crisp Landscape - and absolutely ZERO Blurries!!

 

 

Set visibility to 10nm and uncheck any unused addon scenery in your library.

Or turn off scenery that is competing. Like mesh on top of mesh, or UTX on top of some other sceneries vector scenery.