I recently noticed that my game seemed to be running slower than usual, so I decided to compare the FPS between my current save game and one that I created awhile ago. The only difference between the save games is the addition of a few mods (mostly WMX addons), but I would assume that it would negatively impact my earlier save game as well if this was the cause of my problem.

http://i.imgur.com/0Nnay.jpg
http://i.imgur.com/d9uEY.jpg

Any idea what might be causing this? The game is barely playable in its current state when I try to travel outside.