Fuel Economy After Stage 1 Upgrades (MPG)
 

I've upgraded my car with mainly bolt ons, header back exhaust with catless front pipe, swapped air filters, Amsoil oil change. I've only been able to average around 18-19 MPG!!!! I don't drive on the freeway at all, I'm a student so I drive mostly in residential and in the suburbs.

The second I get in my car I turn on sport and hold down the TC button for 5 minutes so all TC assistance is completely off, it has become a habit, even in the rain (dangerous I know).

I wanted to know what are your averages along with your driving styles and tendencies. Don't worry I'm not with the 5-0, if you enjoy going sideways at 90mph let me know!

Even with occasionally flooring it and people trying to race me almost daily, I average what my Fuelly says below. I was doing 28 mpg till I swapped to 18X9.5's, then I lost a few. Still lots of gas mileage for a car you can have so much fun in.

I've only got a Perrin CAI with inlet and a Nameless axleback currently. Rest of my exhaust is pending order.

Something is wrong there. I have a turbo, that I recently installed so im still in newlywed mode driving like an ass everywhere, and I average ~20 in the city and 30+ highway.

Might be stupid to ask but have you unplugged the battery terminal for 30 secs and connected back on reset the ecu?

You need to log your car...probably a custom tune.

My highly modded out wrx did more than 20.

Yea, something is wrong. I have full exhaust (header, front pipe, cat-back) intake, tune and with E85 I was averaging 22mpg. Im getting around 28-30 on pump gas.

I used to get 16mpg on that fun stuff on my 86. But then again I rarely filled up on it so when I did, I took advantage of it.

I reset my ECU when I got the header back exhaust, but only for about 10 seconds.

10 seconds isn't sufficient to reset unfortunately. I'd recommend pulling the negative terminal for 5-10 minutes. When you start it back up let it idle for 5 minutes and then go for a drive. It'll be slow when it starts out due to the 30% correction factor, but I'd expect you'll get your mileage once it properly adapts.

I have intake/exhaust and even with extremely aggressive in town driving, I usually end up averaging 25-30. On the highway if I'm not exceeding 65, I always get 38-43. Hope this helps :)

Wow that's some bad mileage.

Weird. I drive mostly highway with just catless front pipe and a muffler delete, and I average 29.1 mpg. The only time I really hammer down is merging onto the freeway or passing. :P

Thanks for the response! I'm going to reset my ECU and let it sit for 10 mins, then let it idle for 5. I just pumped gas and will see if it makes a difference.

Even after I've switched to E85 (and have been wailing on it mercilessly since), I'm still getting slightly better than your averages. Keep us posted! Hoping the reset fixes it up for ya.

I have a bunch of bolt ons and am able to get an average of around 28mpg or so per fillup. Once I got 32mpg but half of that was highway driving.