I know there are a ton of threads about these two peices of equipment. I just wanted to let whoever cares know that I have had these on my 8 for about 2 weeks now and after burning through 2 tanks of fuel I am getting 17mpg instead of 13-14mpg pre-upgrades. The butt dyno tells me there is a little more low end power. Also sounds really good.. not like the rice burners.. anyhow.. Hope someone finds this useful. Enjoy and happy moddin'