I want to know why my mpg isn't the same as it use to be. before I modded my car with a catback exhaust I was getting 35 mpg, after the mod I got less then 25 mpg; which I didn't like so I took it off after 3 months. It's now been a week and I'm not getting the mpg I use to get. Any ideas?

Honda Civic 06 ex

 

i'm gonna go with driving techniques/habits

 

I've kept the rpm under 2.3 most of the time

 

TO get the max mpg out of your standard transmission I believe the suggested shift points that are in the book would be a good idea

 

i have the same car, with full bolt ons and i still get around 39ish hw and 33 city.
I shift at mph for gas mileage. I shift at 10mph, then 17, then 25 and finally 35.

OK, go out to your car and unplugg your battery for a good 30 seconds. Our cars ecu is very smart and adapts to how you drive, air flow etc. Give that a shot for starters. As your ecu could be playing a large part in this.

If that doesnt fix it, give me a holar

 

Okay, I'll reset my ecu again and I'll try your shifting suggestion.

 

when was the last time you reset your ecu??? you say again, as tho you've tried this?? I dont want to beat a dead horse if you already know and done what im talking about.

I know this isnt the biggest factor, but where do you buy your gas from. Ive keep very detailed record of my gas mileage and also what station i use, and if you have Kwik trips in your area DONT USE THEM. on avg i get around 5mpg less.

my favorite gas is Shell.

hows your air filter looking? just go over some of the basics and try to narrow it down.

sorry i could be more of a help.

 

this one may sound a tad dumb, but check your tire pressure aswell