If possible, try to compare your K&N to equivalent baseline mileage. That is, try to duplicate conditions and see if it really makes a difference. Prevailing data is that K&N filters don't make any difference at all in most applications, though in some cars where K&N has done a lot of research the filters do help. I'd really like to find out.
Your manual transmission means you can really get a lot more improvement than if you had an automatic. You'll read all about the various ways you can improve here.
I get 32 pretty consistantly with my forrester. Drafting semis on the freeway (3 car-lengths) bumped it up to about 38 mpg on the scan gauge. The racks and tire pressure on my car was worth about 4 mpg improvement (from 28 to 32). Not too bad for a mini-SUV.