I just put 18 $ of 89 in my car and it was 3/4 i drive to a 10 minute place away and back and its already a lil under a half tank of gas... Wtf? Bad o2 sensor ? Please help me.

check tire pressure and air filter they are easy things that cause bad gas mileage after that not sure

just changed the air filter tires are good as well.

First, calculate your exact gas mileage so you can work with some real figures. Fill you tank up all the way and drive until you are almost empty. The gauge is not reliable to tell you your gas consumption. It is normal to get low 20s in city driving.

Next, stop putting 89 in. Your owners manual recommened 91 or above. You should follow it. VQ is a high compression engine and you don't want premature detonation. I think there is a good article somewhere in the FAQs about this.

oh really, i thought 89 was recomended. Thanks! ill st art putting 91 in. Dont you get better gas mileage out of it with 91 and such?

yeah, your mileage will improve with the higher octane.

so do you guys think its just the gas ive been putting in ? Or could it be something else too.

Just a thought - if knock sensor is bad, power will be down, timing will not advance, miliage will suffer.

My mpg has gone up since replacement. Just got @24.5 w/last tank - mostly high speed highway.

i have a feeling all of my sensors are pretty much shot... I just replaced the engine coolant temp sensor cuz my car wouldnt start up in the cold unless i gave it some gas. The rpms would go up to 3k and drop down to 0. But anyway i wouldnt be surprised if it is the KS. But you know what i noticed though too. It seems like my car has more power when i first start it up than it does after its been driven for a hour or so. Dont know if that matters.

only use 93+ gas, i do and get 24-25 MPG

i get bad gas milage cause i drive too fast!

Ant

i guess i drive pretty fast too. So thats probally why. But man im telling you i gotta start driving normal im gonna be poor if i dont. These cars arnt cheap to fill up every 3 days lol.

I drive fast, hard, go WOT many times a day and get about 23MPG average. Don't gauge your gas milage by the gauge's movements. It moves from the 1/2 mark to the 1/4 mark faster than it does from the full mark to the 3/4 mark.

Reset your trip odometer and fill up your tank at gas station A, drive . . . go back to gas station A and fill up your tank again. . . take the miles you have recorded and divide that by the number of gallons you filled up.

Check for exhaust leaks...

Check your o2 sensors

correct me if I'm wrong, but higher octane gas won't help your gas consumption...sorry! This was also in the faqs I believe.

take your car out for a nice long semi high RPM drive on the highway it will help clean out a ton of **** inside and outside of the car. has always helped me out a little.. go to 91 octane.. check for ECU codes?????? how many miles u got

running at lower-than-recommended octane WILL cause premature detonation, and therefore bad gas mileage.

I have just recently checked ECU codes stored i get nothing but 0505 which means nothing is wrong. But if there was something wrong wouldnt my check engine light come on ? It never has come on. I have a 95 se with 112k miles on it. I dont know but this person ****ed up the exhaust he put on an AUTOMATIC... Its all crooked and **** So im looking to get it replaced with stock.

use only 93 you'll see big diff

i do the same but i cant compare to 91 as i always use 93...id still expect a little more milage but i cant relly complain

I just bought

-PCV valve
-Fuel filter
-Fuel pressor regulator
-6 NGK platium single tip plugs
-Inner fender clips (Wont help gas mileage but i still need them)

Im getting very bad Gas mileage maybe like 10-15mpg. So im crossing my fingers after all these things get replaced and I add some Fuel injection cleaner to the tank that I will be back to where I was last month which was around 25mpg...

Oh i forgot to mention before my brother gave me the car nissan "supposly" did a full tune up.. Well my pcv is shot and so is my fuel regulator so this time around i know its going to get done...