Ok, so my dad is pretty tough when it comes to paying for gas especially the way it is around where i live. I just put an SLP Loudmouth 1 on my auto v6 and my dad claims that it now gets lower miles per gallon of gas. When I first put the exhaust on, my biggest fear was loss of low-end torque. I can tell that I did'nt lose that much torque if any at all. What about miles per gallon? Would a less restrictive exhaust lower mpgs?

 

no, you didnt lose any MPG on a catback. now if you did a mid-pipe or headers i could see the computer going alittle rich. But, on a catback I don't see it making a difference. It could just be the difference in driving. flooring it once or twice more than usual right after the exhaust went on.

I still get 17mpg city and like 22mpg highway. and i have 60lb injectors and lots of stuff.

now when you mess with more of the exhaust and bolt-ons and stuff like that a tune might be needed to lean it back out to where it should be.

and yes, a less restrictive exhaust would go alittle rich but not by just the catback alone.

 

your foot probably just got a little heavier because it makes a louder noise now

 

Yea it might just be me. It is a sweeeeet tone!!