97 Civic HX owner looking to learn some mpg tricks in Texas
 

Hi everyone! My name is Noy and I recently picked up a stock 1997 Civic HX 5spd manual with 208k miles that was driven by an elderly gentleman.

Currently i have been averaging 31-35 mpg (A/C on about 80% of the time, yes, its a bit hot here in Texas lol) by calculating it based on gallons each time i fill up. I figured I should be averaging much higher. After doing some research it turns out I have a California spec car (P2N-L22 ecu) and swapped it out for a 49 state spec ecu (P2N-A22 ecu) just today that I purchased from eBay so hopefully that'll help?

I also have a Scangauge and Scangauge-E equipped on the car to help with controlling throttle and load while driving around town. I also plan on cleaning the EGR chamber and doing a full tune up within the coming weeks, so hopefully that'll help my mpg's also.

Anyway, long story short, hopefully I can learn a few things from here to help boost my mpg's.

Regards,

Noy

Welcome to the site Noy. You've got yourself a nice car there. I look forward to seeing you bump up those MPGs.

Welcome! It does sound like the car is probably not going into lean burn. You're on the known right track for fixing it (EGR passage). FWIW, the quickest, easiest, cheapest, least appearance altering mods I found were (1) pumping tire pressure up, (2) installing a lawn-edging airdam, and (3) removing the power steering belt. I drive a 1998 Civic DX Coupe. It's identical to yours in all body and weight respects. The car really does not need power steering.

With your air conditioning, keep it set to the coolest temp and keep the vents set to internal air recirculation and toggle the AC button: off when accelerating, on/off as desired while rolling, always on when decelerating (if you are decelerating with the engine on).

The system will keep pumping cool air for a while when the AC is off, especially if you keep it on recirculation. You'll stay cooler and you'll avoid using the AC when the engine most needs power to accelerate.

Good luck!

Thanks for the welcoming guys.

California98Civic, I've incorporated the A/C toggling (off uphill and on downhill) and upping the tire pressure and It does make a difference. I've also added the lean burn x-gauge code into my scan gauge for further indication when it goes into learn burn. I haven't yet cleaned the EGR passages yet, but I plan to do so. The car has a oem lip spoiler on the front so I'm not sure if that helps with the aero any.

I'll start up a thread to log my progress and any ideas I put to use. Thanks!

Oh yours has the spoiler to? I was trying to find out if the spoiler helps or hurts, but I don't have a consistent enough commute to do accurate tests so I have just left it on.

The car originally came with a factory spoiler when I bought it. I'm not sure if it really makes a big mpg difference, but I like how the car looks without it. Just a personal preference I guess.