“So far so good, I have put about 5,000 miles on the stage 1 right now. Seems to have good pull while towing. I believe the whistle is different, but I might be just changing it in my head.I havent really noticed any change in mpg. My only complaint is it was mailed fedex. I, personally have never had any luck with fedex, it was supposed to be delivered on Friday, I didnt receive it until Monday.”