terrible mpg

[Sexcort89]

hey...i have a 92 escort lx hatchback with 107,000 miles on it. I just recently tuned it up, (k&n air filter change, oil, fram oil filter, new plugs, new wires, new fuel filter, and even that crap 'fuel injector cleaner') and my car is still only acheiving about 18mpg city. 24 highway...Anyone have any ideas of what could be wrong ?

[mark v]

I would say the 107k on the engine and the K+N filter, mostly the K+N is effecting your MPG.

Tire pressure also effects MPG, make sure they are inflated to the PSI rating on the door jamb or glove box tag, never go by what is on the tire (that is max PSI on the tire).

[Sexcort89]

All the tires are filled to the correct pressure, and do you think that the k&n really would kill the miliage that bad? I hear ppl with the same engine achieving 30+mpg while i have 18, thats crazy

[mark v]

K+N filters let more air in, more air also lets in more fuel.

If your transmission is weak this can also reduce your MPG.

Are you running 5W30 oil?

Also if you have a car load of crap effects MPG too.

If your O2 sensors are original they can also effect MPG.

[Sexcort89]

Well i have a system in my car which consists of two 10" subs, a really heavy box, three amplifiers and other misc shit in the car. So that def will affect my mpg, one of my o2 sensors were replaced a few months ago and im running 10w30 oil. As far as the transmission goes, it shifts lol.

[mark v]

Is there one or 2 O2 sensors on your car? They should be replaced in pairs.

[Sexcort89]

that im not 100% sure on. A year back my check engine light came on and when brought to the mechanic he told me he replaced an o2 sensor, I'm not sure if he replaced two or just one or if there is even two in this car...i will look into that.

[mark v]

O2 sensors wear out with mileage and should be replaced at or around 60,000 miles.

[stylingtwagon]

ok ok ok no the k&n will for sure help u but only if u stay OFF the pedal peoplw get a k&n on their cars and gas it more cuz either more power or louder intake sounds
u HAVE to run either denso or ngk uriduim plugs u will get 3 or 4 mpg better for sure
u can also go the the junkyard and get a mass air flow sensor from a 95 escort
the diameter is almost 1 in bigger belive it or not that made a huge differnce
i used to have that motor now i put in the escort GT motor and im geting almost 40 mpg . and its fast as hell !

[mark v]

I am not a fan of anything other than stock spec plugs. I have seen too many running issues with these extra spark or foofydodad plugs. You may gain 1 or 2 HP at the most, you usually will get that just by changing the stock bad plugs with new stock plugs.