Jason. 2006 + have five studs older Civic have four. H

 

I did it to mine also. The MPG loss for me was very little...2-3 mpg for a tank. But, it improves the handling. If you are interested in buying a set you can look over at www.8thcivic.com for sale post for wheels and tires. I was able to find somebody locally selling the for $400 with tires and they just had delivery miles on them. But, for the people that have 2008 models with the TPMS you will have to pay to have your sensors swapped over or pay to have them reporgrammed with the new sensors.