Rep Power: 812

Hey guys, I was wondering why my gas mileage would be so low. Before when I had a short ram intake on and rear section exhaust I averaged 26mpg city driving. Now I have the stock airbox with a K&N filter and I'm down to 24mpg! This is amazing! It is totally stock except for the OEM K&N and a muffler. I always use chevron gas (87), and I hardly ever go over 4k rpms. The A/C is on maybe half the time. I don't know what's wrong.

 
Rep Power: 432

reset ECU

 
Rep Power: 320

Welcome to my world of crap gas mileage ALL THE TIME. I vary between 24 and 27. 27 is rare though. And i dont have an exhaust. I do use A/C alot though but even when I dont, it doesnt change.

 
Rep Power: 401

yup, used to get 330 a full tank, now just tonight infact the gas light came on at 270. it dropped after i put on my CAI.

 
Rep Power: 320

I actually did get 330 to my last tank, and that was with a/c on all the time, and i have an intake and 17's.

But that was rare.

 
Rep Power: 0

i thought an intake and exhaust was suppose to improve things like gas and hp and ****! I get around 300+ to a tank with a/c on and reving near 4k.

 
Rep Power: 812

But my car is stock. I only added an OEM K&N and muffler. Should improve mileage. I've been driving 400+ miles since I put back the stock airbox, so the ecu should have adjusted by now. I don't think a muffler would lower mileage that much. On the sticker it says the average city miles should be 31, or at the lowest, 26. Mine is even below that range. I thought this slow ulev car was famous for good mileage--I guess it's not afterall. And I don't know how some of you with mods are getting 300+ miles while driving hard. It boggles my mind.

 
Rep Power: 0

I guess I'll leave my 03 LX alone. Commuting on surface streets I get 34-35 MPG with the air on if I keep it between 2-3,000 rpm. Running it up to 33-3500 rpm drops it down to 32-33.

 
Rep Power: 0

I had to follow a procedure to reset my ECU when I installed my keyless entry & alarm. If you're interested email me direct and I'll tell you what it was.

 
Rep Power: 812

I thought the ecu was supposed to learn on its own. But I guess I could reset it to see if it helps.

 
Rep Power: 320

I doubt thats your problem honestly.

 
Rep Power: 0

Try these:

- reset your ECU
- change your oil
- change your transmission fluid
- clean your air filter
- next time you fill up, add a bottle of STP fuel injector cleaner (or similar product)

Some of those are easier to do than others, but I regularly get between 300 and 400 to a tank, and getting over 400 miles is actually quite common. I once managed to go 501 miles on a single tank, but I have yet to duplicate those numbers.

Anyways good luck man ...


Note: I've gone 270 miles on my current tankful, and I still have a quarter of a tank left. Plus I've been revving hard a lot since my last fill-up, mostly city miles.

 
Rep Power: 320

I have done all that....(except change my tranny fluid).

The most I have been able to get outta a tank was like 330. This time to try and help my gas, i put in mid grade 89 octane (even though i knew it would DO nothing) just cause so many people on this websight say they get better gas mileage on mid or prem. grade gas. So far, its not working for me. Im at 170 and below half a tank. But that means nothing because our gas guages are pretty inaccurate.

 
Rep Power: 362

well ... seeing as how nothing else seems to work ... you guys also might wanna try one or both of the following ...

1 - gap/regap spark plugs ...
2 - change spark plugs (iridiums wrk great)
3 - MAKE SURE tire pressure is at 30 or higher for stock (30-34)

... I remember I got about 290 until the gas light came on and that was consistant for about 5-6 fill ups ... then I noticed (yeah, finally) that my tires were low on air ... it turns out it was about 23-25 psi ... I then filled them to 32 and immediately following, my next fillup was at 340-350

 
Rep Power: 0

I have an 01 EX, and i use 91 octane usually. I usually fill up at a quarter tank... around 300 miles... and my gas light doesnt come on til about 400 miles when I push it. I live in Phx, so its like 200 degrees outside, but I dont run the ac, since the compressor died a few weeks ago. But, I do run my engine hard, I shift at 4k, but a lot of times i take it to 7k, just because i feel like it. So its not like I baby it.

 
Rep Power: 0

Don't forget that those EPA mileage figures are gathered from tests done under absolutely prime conditions.

If you want to see how good your car' mileage can really get, try shifting at 3000 on each and every shift using light, smooth acceleration... and use cruise as much as possible ... and pump all your tires up to 32-33 (measured cold). Drive like a granny... literally.

I know this is going to be tough since our cars are so easy to rev, but do this for one full tank and you'll see what your car's real mileage is under "friendlier" conditions.

 
Rep Power: 812

Here were my conditions:

-driving like a granny
-just had oil change
-air filter is new
-gas is always chevron with techron
-tire pressure is 30psi

I just reset my ecu, so we'll see what happens.

 
Rep Power: 0

Update:

I finished the tank off on the highway and when I filled up I was at 409.4 miles

Usually whenever the pump cuts off, I put in like another dollar or more ...

 
Rep Power: 0

i fill up once a week, and thats all i care about

 
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When you say 24 mpg, is that for 100% city driving ... like all stop and go? If that's the case, then maybe that would explain why it's so low. From my own experience, 100% city driving almost never matches EPA city figures... but highway driving seems to come close to EPA hwy figures. But if you're doing 50/50 city/hwy, than yeah, there's something wrong with 24 mpg.

I hate paying for gas (I'm in the most expensive state for gas), so I hardly ever shift above 3200 (unless I'm merging)... and I'm getting 35-36 mpg regularly with 30/70 city/hwy.


edit: ... and I find Shell regular gives me slightly better mileage than Chevron regular (and Shell has been advertising that their gasoline gives higher mileage too)... WTH, you may as well give that a shot

 
Rep Power: 0

Man, I think I will find some wood to knock on! I have an 03 LX and do 80% freeway. I run my a/c about 25% of the time. I shift about 3500 and never go over 4000. I get at least 415 miles per tank. I would be PISSED if I got what I see reported. Just my .02

C

 
Rep Power: 0

How do you do this? Disconnect the battery and reconnect?

 
Rep Power: 812

The 24mpg is with 75% city and 25% highway.

 
Rep Power: 812

RESETTING THE ECU:

1. Either disconnect negative terminal from battery OR pull out fuse underhood labeled FI ECU and wait 10 minutes.

2. Start car and let it IDLE for 15 mins (no giving it gas!)

3. Turn off car

4. Turn car on and off once again.

5. Start car and go for a drive.

 
Rep Power: 0

Thanks, gearbox.

 
Rep Power: 362

yes don't use chevron gas ...

well you could, but at least for me, it gives me less gas milage than anywhere else. I have yet to try arco. chevron used to give me kickass gas milage, but ... eh. I go with mobil now ... gives me the best

 
Rep Power: 0

Don't use Arco ... terrible gas mileage from my own experience, and and some loss of power and smoothness in my engine too.

Only 3 brands I would consider using now is Shell, Mobil, and Chevron.

 
Rep Power: 812

I only use chevron because of the additives it has to clean the fuel system.

 
Rep Power: 394

I have great gas mileage now. I dont know what is goin on. I drove from outside Kansas City MO, and bought the regualr 87 octane at Quiktrip. Filled up, and got 41 MPG. My trunk was packed full of **** too. and this isnt the first time, this is the third time its been that good. I also have a K&N drop in filter. At the same time i put the filter in, I ran a bottle of 3M Fuel Cleaner. That I think helped. I also have stock tires at 32-33 PSI. http://forum.mnsportcompacts.net/viewtopic.php?t=8927 Check that thread, I posted that thinking it might have to do with the gas i bought.

 
Rep Power: 564

I know you're refering to city driving but I actually don't find my car that bad at all. I reset the ECU when I had my CAI put in. I also have a header and cat back TCS. On the highway (when travelling) I cruise at 140 km/h with the RPM's at just about 4200 therefor keeping the VTEC from engaging. That helps lots!