This might be just a situation particular to my car, but, ever since I took my stock air box out and replaced with a cone filter, my mileage dropped about 5-6 mpg in the city, and about 2-3 on the highway. Now I have rebuild my intake, and I have pulged the air temp sensor into my new piping (before it just used to dangle in the engine bay), and my mileage is still the same. Though, I also need to consider that I have yet to change my fuel filter or professionally clean my injectin system, therefore, I think that the cone could be a coincedence. But I want my mileage back! Gas prices are not going down anytime soon now. Its $1.60 for me now, and it will be hell of a lot higher if our monkey of a president, George W. Bush, decided to unleash his childhood anger on Iraq, where the UN inspectors still found NOTHING. But thats a whole new story there. Back to my point - I want my mileage back!

 

More air=more fuel=more power.

However, the biggest impact on mileage isn't anything you put on your car, it's your driving style.
If you can resist the red blooded right foot urges, try driving a whole gas tank just to see what kind of mileage you can achieve.

Try:
no idle running (a car sitting gets zero miles to gallon on the gas it's burning)
shifting earlier (more rpm equal more fuel)
no wide open throttle
try taking off from the stoplight at the same speed as everyone else (instead of dashing out front)
coast whenever possible...hill, approaching a red light etc
see a red light ahead? Take your foot off the gas as early as possible, hope it changes before you get there. You can leave it in gear and engine brake also.
draft semis on the freeway....a couple car lengths is adequate to see an improvement.

 

I agree with your point, I do like to drive fast, not all the time, but I do. And I have been driving the same even before I build new intake, and my mileage has been very good before. But my general idea about intakes was, the engine is sensing colder air coming in, thus less gas is supposed to be used during the combustion process. Thats is why, before, when my air temp sensor was simply dangling in the engine bay, I thought as though was providing wrong temp to ECU, or not reading correctly (because there was no air flow). Now I have everything plugged back in, and the air temp sensor is now measuring the temperature of the flowing air, but I still see no difference in mileage. It is rally sucks, because on my DX model, Gas Gauge on the cluster is so big, I can see my needle drop down little by little, after everytime I make a trip less then 20 miles.

P.S. I wish I had a manual tranny.

 

I'm not positive on this because I know more about Hondas MAP sensors than Mazdas MAF sensors but I'll apply some common sense observational engineering.

The CAI does two things...it supplies more (a)air flow at (b)a lower temperature. Lower temperature air is more dense i.e. more oxygen, better for power.

I would guess the MAF is reading the increased air flow, telling the ecu to supply the appropriate fuel, according to the ecus fuel maps

I would guess the Intake Air Temp sensor also contributes to the ecu. Since you were reading intake temp from inside your engine bay before (when it was unplugged), it was probably injecting a value from the fuel table at, say...90 degrees.

Now that the IAT sensor is reading the outside cold air intake temp, at say...50 degrees. The ecu is compenating with even more fuel for the denser air.

More fuel injected=lower mileage.

I forget the exact dtails but the formula is something like for 11 degrees you drop the intake temperature, you get a 1% increase in HP...this is one of the reasons CAI work so well.

That's my guess anyway.
The only thing that I've ever done that actually improved my mileage noticeably was an exhaust. MPG on freeway trips went up substantially.


You want a better gauge cluster? I've got that LX cluster with the tach that I'll let go for cheap...it plugs and play, I did it on my dx.

 

I installed a Ractive Intake, and plumbed the IAT Sensor in the inlet tubing... Big mistake, milage dropped from 31-32 highway to 27, and the car ran rich, (Black tailpipe). I took the IAT out of the airflow & tie wrapped it near the battery, and... 31-32 again, and the car runs MUCH better, before it felt sluggish. I think the air rushing past faked it out to think it was always cold and needed to run rich.

 

yea, i've noticed the same thing ever since i put my ractive cone filter on. i drive up to school alot and i noticed a big difference in the mileage cuz i use to measure it. i drove exactly the same with exactly the same wieght and everything. so is it suggested that i move my sensor close to the battery and not let it dangle near the filter?
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lesbians Webcam

 

im getting worse mileage too...i try to drive a full tank without getting on it but its sooo hard especially on the freeway when people are driving slow as hell lol

 

Just keep the sensor out of the airflow, and up out of the way somewhere where it won't break. I drive my Protege 150 miles a day round trip to work, and try to go a full tankful "roundtrip" to the gas station every 2nd. day, about 330 miles on a tankful (when the red light goes on). I don't think the tank is empty, but I don't want to get stuck on the side of I95. So when the mileage dropped off, I couldn't go all the way back to my "home" station (read cheap gas!). Well anyway, that fixed it!!! Actually, if I run hard on the highway, 70-80 MPH,with a few full throttle passes, it only goes down to 29-30!!!