Basically what the topic says. I can run Skyrim on modified high settings at 40-50 fps outside and 60 fps inside but in Oblivion I cant get over 30 fps.

Windows 7 Ultimate 64 bit
Radeon HD 4690
8 g's of Ram
quad core cpu q6600 @ 2.40 GHz, 2403 Mhz

Can you guys help me?

To be honest, I think you're doing okay. Skyrim seems better optimized than Oblivion to handle modern PC hardware, as is fitting for a six-year newer game. My Skyrim install has all sorts of hi-res textures and such thrown in and uses the highest in-game quality settings, and is for the most part smooth as silk. Modded Oblivion, on the other hand, can stutter a bit as new cells load, and in one isolated areas borders on slide-show. This is with a somewhat more powerful CPU than yours (Intel i7 930 2.8ghz, 6gb DDR3-1600 ram, Nvidia GTX670 4gb). As I recall, part of the problem is that Oblivion's engine doesn't perform 'culling', meaning in renders everything within a certain distance whether seen or not.

To each his or her own, but in my opinion 30fps isn't bad at all.

One thing that can help a lot with stutters (which you don't mention) is Oblivion Stutter Remover. If you don't use that utility give it a try and monkey with its Heap Replacement settings. It can do wonder for making the game run smoother, if not necessarily faster.

-Decrepit-