dont know how but on the highway im getting better gas mileage... all i did was pop off the mufflers in the back cuz I wanted some open sound (which really sounds nice...) and now Im cruising at 80 just under 3k rpm averaging 30 mpg, it used to be 26-27, any ideas as to why....and will this open exhaust mess up the car?
honestly when i first did it, it sounded ok but was running poorly, did the DME like tune itself or optimize or whatever?
