I own one here and I use it in my Mazda V6.
1) It is NOT a good idea to use K&N air filters altogether in Pakistan and there's a very simple reason to it. The K&N filter is designed with microscopic holes in it that are larger than paper air filters. This way, they let more air in, but they also let more fine particles in with it. They ran tests over here comparing K&N and other air filters side by side to see their filtering ability, and they found that the K&N filter can harm your engine in the long run- and these filters come with a lifetime warranty, so you will use it for a while. End result is that in Pakistan, you risk throwing a lot of dust and dirt into your engine.
2)No increase in horsepower at all. I checked it time and time again by running quarter miles with both air filters, and there's no difference. It did improve my mid-range acceleration since my engine is really restricted as it is, and this opened it up considerably.
My advice is to stay away. There aren't many gains, and the filter isn't cheap anyway.
