exhaust

Go with a flowmaster dual tip muffler, they sound very good and look clean too.

Warning if you a put a really bug exhaust on your subie, you could blue your cats, as well as a cdi, if you put one in... just a Lil FYI

Blow not blue *

Just don't go over 2.5" diameter so you get a decent flow rate. Try not to go with "universal mufflers" because complete systems are designed with a consistent diameter which works out better. If you're more interested in sound quality than absolute performance, Remus exhaust systems are sound engineered. At least they used to be a couple of years ago, I'm not sure if they still focus on that.

Should I assume you have a base Impreza and not a TR, WRX, etc.? To improve gas milage, make sure your tires are properly inflated, have a light foot instead of a lead one, drop-in K&N filter, and keeping current with scheduled maintenance all will help with gas mileage. As for exhausts, assuming that it's not a turbo model, any cat-back exhaust or muffler will be fine. These do nothing to affect performance and only modify your exhaust note. Before buying one, do some research and listen to as many sound clips as needed until you find one you like. If you're not in a hurry, go to some meets/gatherings and listen to them in person. Everyone's tastes differ, so what one person thinks is fantastic, another might hate it. Because of this, you really need to listen to them yourself. There are sound clips listed on www.clubwrx.net, www.nasioc.com, www.iwsti.com, etc. Keep in mind, most soud clips will be for WRXs and STIs, so they will sound a bit different on a non-turbo car, but it will at least give you an idea. I hope this helps. Good luck!

Will a 2020 WRX exhaust system fit a 2020 impreza