Keep in mind that tires themselves are quite heavy when considering wheel size. Because there is more rubber on the 15" wheel, the wheel itself will be lighter than the 16" but the tire is heavier. IMO you're better off upgrading to the 16" size and getting the handling benefits especially if you're considering a light weight wheel like the Kosei K1 where the difference in weight between 15" and 16" is minimal.
Don't know if there is any fitment problem but I considered the Kosei K1 back when I was looking at wheels. I ultimately rejected them because of the offset (which is important for handling and tracking too).
If I may suggest something, take a look at the 5Zigen Fighters at http://www.discounttiredirect.com. If I remember right they weigh in at around 15lbs for 16" and have a perfect 42mm offset for our cars. I've had 'em for 2 summers now and I'm pretty happy. In between the spokes can be a little hard to clean but not too bad and they are powdercoated so they will chip if you're not careful. The price is right though. Click on my sig to see how they look.
Don't know if there is any fitment problem but I considered the Kosei K1 back when I was looking at wheels. I ultimately rejected them because of the offset (which is important for handling and tracking too).
If I may suggest something, take a look at the 5Zigen Fighters at http://www.discounttiredirect.com. If I remember right they weigh in at around 15lbs for 16" and have a perfect 42mm offset for our cars. I've had 'em for 2 summers now and I'm pretty happy. In between the spokes can be a little hard to clean but not too bad and they are powdercoated so they will chip if you're not careful. The price is right though. Click on my sig to see how they look.
