Hey Guys
I dont post much but need some advice. I got a 2001 SE with about 89k miles on it. I drive mostly city as I drive in and out of boston everyday. I used to get 250-300 miles per tank. Lately I am getting about 200-225. Is this just due to winter gas and cold? Last winter it never got this low then again I was doing a bit more highway.

Just seems odd that it drops that much from last winter.

FYI I had an engine light go on about a year and a half ago and Nissan flashed the computer to turn it off and reset some thing that were amiss. I was told it was pretty common that my car needed to be flashed.

Any ideas let me know. I also use 89 gas and never anything else.

 

Your car is designed to run on premium gas. You should be putting in 91 octane or more. Try it for a couple of tanks and see if your mileage improves.

 

Couple possibilities:
Bad O2 sensor
Air filter really really dirty
Clogged fuel injector (get some injector cleaner at AutoZone)

All of those I don't think would hurt the gas mileage that bad, but if you have all 3 it could...

 

Air filter is brandy new I replace them everytime I do my oil.

As far as 91 goes, I have owned 2 5th gen maximas and till now I never had an issue running 89.

I will run some sea foam through it. The car is gone come the spring anyways just trying to get it there.

 

WillMax01's suggestions are all good. You may also inspect:

* fuel filter
* make sure tires are properly inflated
* check out the brakes

Your catalytic converter could be clogging, too. Any reputable shop can check that for you.

Why selling in the spring? Just ready for something new, or are there other problems with it? Just curious.

Thanks,
Chris

 

seriously. we have 1 of these gas mileage threads once a month. there must be at least a dozen different ones out there.

 

buy another maxima?

spark plugs and a PCV valve? Might help

Oh and fill the tires with Nitrogen NICE little boost in gas mileage

I get around 330 with my 3.5L

 

I am selling in the spring to buy a smaller 4 cylinder car. I drive in and out of boston everyday and the gas mileage is killer.

As for the tires I do have one tire going down that I am getting fixed saturday but I keep it inflated and its a rear.

Check the brakes? I assume you mean lift the car and be sure none of them are dragging.

Where is the fuel filter and how hard is it to change?

 

if you don't like it, sell it.
my suggestions are:
check tire presures
replace air filter
stop warming your car too long
drive smoothly
use better gas.

 

seafoam won't heal a damaged engine remember.

 

If the check engine light was for one of the 02 sensors, that could be the cause. As these sensors go out, they get lazy, ie.. allow for a rich mix

 

hmm this information actually helps cuz i've been running 87 for a bit recently...and i've been getting some pretty bad mpgs...

 

Wow cheap azzez how the fack are people so fken cheap on here wow you run 89 your engine might go to **** just so your cheap *** can save a faken dollar on a tank, and then you tards post oh my engines runing funny help, oh car feels sluggish when accelerating, stop eating fken twinkies at work and you can buy that tank of premium = better performance, engine safety, better mpg,

 

Couldnt have said it any better.

 

Im shocked

 

Go jump off a bridge, but shoot yourself in the face as you're starting to fall.

 

ill see you on the way down I could use your pathetic self to break my fall

 

what the gay.

 

I get about the same with all city driving. Just use a Prestone Full System cleaner and run on 93 from now on.

 

definitely run the right octane for your car.. 91+.. that's probably 90% of the problem right there.. do that, THEN worry about all the other crap like 02 sensors and plugs and all that.. the price difference between 89 and 91 probably comes out to less than a dollar per tank, and you'll actually save more than that by keeping the gas in your car longer and not having to go to the pump as often.. just use it, and enjoy better performance, better gas mileage, and more money in your pocket

 

There is no fuel filter.
We have a "Fuel Strainer" attached to the pump in the tank.
If you want to change that out then you have to remove the back seat, take the fuel pump out through the access hole and take it apart. Once it's apart you replace the fuel strainer, put the pump back together, then re-connect the fuel lines, put the pump back in the tank, replace the back seat, and let your car air out from all of the fumes.

 

Well thanks for the people who posted useful info. As for the higher octane gas I still dont agree. I was getting 300-350 mpg's with 89 with over 60k miles between both my maxi's. Now this one decides to go down. I am getting the car diagnosed this week. My bet is a faulty MAF or O2. Thanks again.

 

oh.. well than yeah, there probably is another problem... but i'm willing to bet you that your mileage will improve beyond that if you use the correct octane that your engine was designed for

 

well using the 89 octane slowly affected the engine and now you fuxxed it up .. just a guess :shrugs:

 

why the fak is this thread still open?

 

#1- anyone else tried this before and does this work?
#2- where can you get nitrogen from to put into your tires?

 

just put helium in it ... any party store will have it ..