low mpg

[89civicguy]

i know that mpg goes down when you tune your car but 14 mpg is rediculus, i'm thinking about going back to my 93 camry because of gas cost alone, and i love my 89 civic, is there something up, if all i have done is put a cold air intake on it and i am only getting 14 mpg, or is that normal?
Kyle

[Sparsky]

unless your going full throttle all the time, then something is up. I know when I first put my cold air intake on i went from 42mpg to 32, but I was driving it hard. Once I went back to how I normally drove the MPG went back up. Got a check engine light on? make sure all vacume hoses are connected? what engine do you have?

[EF You]

when was the last time you did a tune up? plugs, wires, cap, rotor, fuel filter? try running a fuel system cleaner in your gas if you normally use cheap gas. Shell makes a gas called V-Power that has an excellent additive package already in it that ive personally experienced on my del sol, and it worked wonders. when i got the car, it was getting 25 MPG, after two tanks of V Power, im getting 30 MPG, and i didnt do anything else to the car except gas it up.

make sure your ignition timing is correct and that your idle isnt too high. try to get the idle below 1000RPM, 750-800 is a good spot.
i know you just put an intake on it, so i doubt that the air filter is very dirty.
also, has your trans fluid ever been changed? if it hasnt, or it has but with the wrong fluid, it could be straining the gears, and you have to gas it more to get moving. change it with honda MTF.

another thing, which grade of oil are you using in your engine? if its too thick, or you filled it too much, you could be stressing the engine as well. the crank doesnt like to swim in oil. if you dont have any oil leaks, and you dont burn oil, then try using thin oil, 10w30, 5w30, even 5w20 if your engine is in really good shape. amazingly that does make a difference in your MPG.

the last thing, check the pressure in your tires. if you arent running enough tire pressure, you make the contact patch on the tire too big, and more friction with the road means you gotta gas it more to move. too much tire pressure and the tires will heat up a lot, and again, more friction. go with hondas recommendation for that chassis, which is 32 PSI, not the recommendation on the tire, since that tire has no idea which car its on, and the rating on the tire is just the max pressure the tire can safely handle.

[turtlecrxsi]

Incucivic has mentioned a bunch of good points. A new fuel filter, new spark plugs, maybe even a new 02 sensor and reset ECU (use search button) will help. Also, like the man said, tire pressure is important. Do you have big rims on your car? Big rims mean more weight which means more rotational mass the engine must move.

[Exempt]

After u installed the cold air intake, did u reset the ECU?

[SiZ]

So, you added the intake and immediatley your gas milage went down more than 50%!??!

[icE_x]

I think its the oxygen sensor if it went down drastically after the intake install. My guess would be that your ECU is telling your car to run extremely rich.

[livinincalifornia]

wow 14mpg..that's extreme, surprised your motor isn't bogged down with gas. When I had a bad O2, no tune up and an error code running on injectors I still got around 26mpg.

[89civicguy]

no, i didn't reset the ecu, how do you do that? i'm doing a whole bunch of tune-up things with plugs and cables today so i hope that works, i can't afford a car like that. no i have no new rims on the car, but i just got brand new tires and they are probably up to max because the tire place did it...that's one thing i don't care to learn to do, tires...i didn't check the mpg before i put the intake on it, but i had driven on less than a 1/8 tank for about a week driving about 10-15miles a day. i just got this car from arizona, and the previous owner didn't even give it an oil change in 3 years, so i guess i've gotta pick up the slack. i'm gonna try the v-power thing after i change the plugs and cables. thanks a lot i hope this works. i love my civic, but i can't afford a 14mpg car.
Kyle