what could be the cause of my poor gas mileage? i just changed plugs and intake filter and my mileage is so much lower than pre swap.

preswap, i was getting 250-280 per tank. postswap, im getting like 200. im using a phearable ecu. 240 across compression jdm itr

 

Do you have a heavy right foot by any chance?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EG type GTR &raquo;</TD></TR><TR><TD CLASS="quote">what could be the cause of my poor gas mileage? i just changed plugs and intake filter and my mileage is so much lower than pre swap.

preswap, i was getting 250-280 per tank. postswap, im getting like 200. im using a phearable ecu. 240 across compression jdm itr</TD></TR></TABLE>

What kind of motor were you using before? You must drive like a jackass to get 250 a tank, I drive a boosted d-series on 450cc injectors and I get 350+ miles per tank. That ECU program might also be the culprit.

 

well its 250 city driving with plenty of stop and go.

i had a stock eg cx. now i have a jdm itr. i dont have a heavy foot most of the time and cruise around 3krpm 5th gear.

what are the possible culprits to poor mileage? its kinda odd that my mileage goes to **** right after the swap. i dont smell gas in the car so i dont "think" running rice is my problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EG type GTR &raquo;</TD></TR><TR><TD CLASS="quote">i had a stock eg cx. now i have a jdm itr.

what are the possible culprits to poor mileage?</TD></TR></TABLE>

You answered your own question. Your car now has more power, larger injectors, and MUCH shorter gearing. Your engine is naturally using more gas and your tranny is keeping it higher in the revs. Sorry. Going from one of the most fuel-efficient motors for a civic to the highest HP 1.8L production engine ever made, you're not going to see the same kind of gas mileage. Sorry.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EG type GTR &raquo;</TD></TR><TR><TD CLASS="quote">i had a stock eg cx. now i have a jdm itr. i dont have a heavy foot most of the time and cruise around 3krpm 5th gear.

what are the possible culprits to poor mileage? its kinda odd that my mileage goes to **** right after the swap.</TD></TR></TABLE>
This is what I am hearing:

"Okay, I had a stock D15B8 which is known to get over 40mpg. Then I swapped in a JDM B18C spec-R - known to get less than 30mpg - with an aftermarket ECU program that isn't tailored to my needs and likely runs pig rich. Now I get fewer miles from a gallon of gas than I did before the swap. Why has my car's fuel economy decreased?"

 

reason why im asking is because some R owners still get 30mpg with ac on