Should my MPG go up if I install, say, an Injen CAI and/or a Magnaflow Muffler exhaust? And I'm talking about normal city driving.

 

The difference would be minimal if any at all. Most guys see it go down pretty dramatically because they love the sound of it and are stomping on it everywhere they go.

 

If any differences they are minimal. If that's what you want out of a CAI and muffler, look elsewhere for MPG increase.


100% agree with this statement lol

 

lol I have a CAI, muffler, and spacer. I just filled up and I got 340 miles out of a tank. our cars have 20 gal tanks so I probobly had only 1 more gallon before I filled up.

340/19= around 18 MPG. lol yes I rounded...

Now im not saying the mods are to blame...well yes they are actually...

 

The mods, intake and muffler have zero effect on your mileage. What does effect your mileage is your listening to those sounds you enjoy hearing which starts at your brain and ends up at your right foot. If your main concern is mileage keep it OE or buy a Kia....Gary

 

Technically, by increasing the efficiency of an engine (power) you could consume less fuel by not putting as much load on the engine for the desired effect.

But there are too many variables like the shift of the powerband to a higher rpm range needing more fuel to produce said power.

I did notice on long highway drives a spacer is worth ~2mpg.