2012 Chally RT, 6 SPD
I added the spacer on my 2012 R/T. Whistle was VERY SLIGHT, much less than most noted IMO. I DID do a b4/after mpg test by resetting the car's MPG counter, drove VERY similarly, added the spacer, reset MPG counter and drove approx. under the same conditions, and REALLY noticed mpg increase (about 3.5-3.8 MPG BETTER, so pays for itself. Power wise, maybe a BIT MORE low end TQE, or cud b just better response. Only complaint, had to use long bolts vs instructed short ones. WUD DEF RECOMMEND!!!!!