I was just wondering if replacing the exhaust will help gas mileage. I remember I read something about the maxima exhaust that the muffler has a valve to shut off one of the exhaust outlets to improve mileage. I guess that implies that having a restrictive exhaust does increase mileage. I was wondering if it actually decreases mileage.

 

anyone know anything??

 

theoretically, yes. but the sound is intoxicating, i found myself getting on it more in my old 337 just to hear the sound. yet i still got better mileage with that then my evo. 'tis the tradeoff for the car!

cheers

 

u wont see much of a decrease at all...

 

For the Money you spend for some of these nice exhaust systems I really don't see it as being something anyone should do as their first, second, or third modification to this car.

I had a 97 Eclipse Turbo, and I can tell you, after spending over $800 in an exhaust, it was a complete **** of money. Really the only benefit is a somewhat nicer sound, and for $800-1000 dollars, it's just not worth it.

There are better things to spend your money on at first, exhaust would come down the line a bit, I'd say after you've added 30-40 more HP.

 

I would think that a better flowing exhaust will increase mileage - it does on N/A cars. Engine efficiency goes up.

However it does cause you to stomp on them more often - that's been my problem.

 

Thanks for all the responses. The reason I'm asking is because my cousin and I got into an argument about exhausts. In response to me saying that exhaust gets you more power and better mileage, he was asking why it just doesn't come like that from the factory. And I said it would simply be too loud. This is the main reason, am I right?

 

or that it would cost more to design it