ok. First off, let me say that I"ve already searched this topic. I have done the following things to my car as maintenance. I bought a 94 integra LS 125k with automatic transmission.

1. Sea Foam-ed the engine
2. Cleaned Throttle body, then changed the oil
3. New spark plugs, wires, and rotor cap
4. Alignment and rotate and balance on new tires
5. Changed transmission fluid- Honda ATF
6. Flushed radiator and changed antifreeze

I did all this on thursday. Then I filled up my car with gas thursday to the full mark, and put fuel injector cleaner in the gas tank when I filled it up. I have gone 104 miles since then, with the AC both on and off, and I have HALF a tank of gas!! What the heck is up?

The only other thing that I can think of off my head would be the O-2 sensor, but wouldn't the check engine light come on or something to let me know if I have a bad oxygen sensor and my engine is running rich/lean?

What else could I try to increase my MPG? This is driving me nuts, because I drive about 70 miles a day to work- and need good gas mileage! Help!!!!

 

well first of all you have a 13.2 gallon tank and your car should get 24-30 mpg considering it over 100k take 2mpg off that so your getting probally 22-28 take 1 mpg cause it a auto thats 21-27 your tank scale is 8-10 gallons I forget say 10 so 10 times 23.5 is 235 miles a scale tank 104 times 2 is 210 so your probally getting about 21 miles a gallon change your air filter and spark plugs that should help get a CAI that will also help

 

sorry I din't see that you change the spark plugs also check to see that their is'nt any ecu mod chips umm thats weird but its not to far off this will restrict air flow for performance perpose but get a turbonator or spiralmaxs it goes in your air intake manifold you can get one at kragen or autozone I believe i would'nt recomend it thought if you plan on supping up your car

 

The SpiralMax and Turbonator do nothing but obstruct airflow.

And for the love of GOD, use punctuation.

 

u asked about the 02 sensor...ur o2 sensor like every other part does wear...it can and will operate incorectly without the check engine light coming on becuase although it may not be operating like it should it still registers within the the computers norm...there are good shops out there that can chekc all the emision and fuel sensors on your car and tell u which ones are failed, going to fail, or operating incorrectly...all they do is check what the sensor is reading against what the books say it should be for optimal performance

 

Alright, let me see if I can talk you down a bit.

Up to this point, you've done all the right things in terms of maintenance. If the Oxygen sensor had died you'd be seeing a check engine light.

I'll bet that you are getting better mileage than your gauge leads you to believe.

Our gas gauges are horribly inaccurate. The only way to make a meaningful assessment of mileage is to do real math. (Divide the total miles driven by the quantity of gas consumed.)

Case in point:
I own a 97 LS 5spd with about 110K on it.

My weekly commute is shorter, but it is entirely stop-and-go suburban driving. By the time my needle gets to the halfway mark, I only have about 100-110 miles on the trip meter.

Now I reset my trip meter with every fill-up, and calculate my actual mileage on each reciept from the gas station.

When I do the math, my actual gas mileage averages between 24 and 26 mpg... perfectly normal for an enthusiastically driven manual Integra.

Here's the data from my last fillup.
5-12-05
Start Mileage: 107936
Ending Mileage: 108161
Distance Total: 225.0 miles

Refill: 8.600 @ $2.599/gal

MPG CALC: 225 miles ÷ 8.6 gal = 26.162 mpg

Run the numbers and I think you'll be pleasantly surprised.

 

2.59 a gallon dam...here its 2.31 for premium. I get about 300-330 miles a tank. after i put my o2 sensor in though now i only get 280-310. you think thats a bad o2?

 

That kinda what I was try to say. David has it right on the point.

 

And that $2.59 is for 87 octane. :eek4:
It's $2.99 for 91 octane.

Re: o2 Sensor input...The only to be absolutely sure is to connect a diagnostic tool [or multimeter] and read the o2 sensor voltage.
That said, I doubt that the o2 sensor is the cause.

My 2.5 year average MPG is currently 26.079.
But on a single fillup, I'll usually alternate between 24 and 26 mpg.

Coming back from SEMA last year, I saw 31.8 mpg between Boron and Buttonwillow, CA.

 

dave man i feel sry for u by me 93 octane is at 2.40
sweet jesus 2.99 for 91 i would jump of a building