So since I put the K&N intake, the BD TD and the BD muffler on my 06 the mileage has gone down. When I used to tow my boat when I was stock I was getting 14 to 14.5 mpg now 12-12.5. I got the BD TD set at tow and I'm not driving it any harder than I did stock. Is the intake chip and muffler working oppisite for me.

 

With an open exhaust and open intake, your milage will suffer, the TD will help bring some milage back I would think if it's on the lowest setting... anything beyond that is going to add fuel. My edge on #1 does not add fuel just adusts the injector timing.

when I added my AFE intake, milage went down slightly, then when I did the exhaust mods, basiclly straight thru, milage went down more. for the hell of it I put the stock intake back on and milage came back about 1~1.5 mpg. this also agreed with my butt dyno letting me know that there was more low end torque.

get more low end torque and your milage will come back.