Hey, Anyone know what realy happens to your fuel economy when you install a Borla or Stillen or any other Cat Back exhaust system? I have heard it will get a little better, and I have heard it will get alot worse. Whats the truth? If I can get more horses and better fuel efficiency its a no brainer. But will it pass inspection?


G35C

 

I am ordering an exhaust within the next week, and yes, you will get BETTER gas mileage. I have had an intake and exhaust on every one of my cars, and have always got better gas mileage. This is the thing, most people dont drive normally when you have an intake and exhaust because it sounds so damn nice. But if you drive normally, you will definitely get better gas mileage.

 

I appreciate the response. I have heard that from a couple people now, I gues I was sceptical hearing it from the guy at the spead shop first. Now, what exhaust to get, hmm. I was thinking Borla or Stillen, which did you order.

G35C

 

Theoretically and physically, it will get better, however your MPG will get worse. Mainly because you'll have a heavier foot to hear the exhaust!

I'm POSITIVE that if the stock exhaust didn't sound so frikkin cool, that my milage would be above the 17 I'm currently getting.

03.5 6spd DG/G aero pk/kit
He who makes a beast of himself gets rid of the pain of being a man.

 

Well I have an Injen CAI and Borla true dual exhaust on and I get the same if not better gas mileage as long as I don't drive with a lead foot. More than likely you'll get worse gas mileage at first because you want to hear the sounds and notes, but with time you'll learn how to drive normally again. Hopefully after installing the Borla headers, I'll still be in the 20+ MPG if not better