Hey guys i got a 2002 nissan maxima SE .My gas mileage is soo horrible thats its starting to **** me off even when i dont drive hard. Car has 85k new filter/new plugs/Tire pressure is even all the way around and set to factory spec. Trip computer says 18MPG usually but im deffinately not getting that maybe some sensor is going please let me know..

 

im having some problem probably similar to you b/c i do NOT ever get above 18mpg...even when my parents drive my car. everything is fine regarding tire pressure, air filter, gasoline, plugs, etc...so i'd like to know whats causing my sh!tty gas mileage. did seafoam and it didnt help

 

yeah i always use 93 Oct and the max is just eating gas like crazy

 

what's seafoam?

 

Its a product used to clean out everything in the car to restore performance/gas mileage

 

I'd wager something is causing your ECU to run in Open Loop mode all the time... that TRASHES fuel economy. Bad/disconnected oxygen sensors, possibly a few other things. Take it to somebody who has an OBD-II scantool and can check if there's anything up.

 

No codes present on mine

 

Do you add it to the gas? Can I get it at any auto parts store?

 

Do the Seafoam..."Advance auto parts and Autozone" $4.00 , read the instructions.. a follow them. It will work like magic in your car.

 

Thanks Lontar1!

Boiler up! ( I went to Purdue and sadly I was in the front row at Ross-Ade when you guys converted 4th and whatever for a 35yd TD pass at the last second. At least you won the national championship, that made it a little less painful.

 

hey man--gas mileage is such a bad subject b/c people always assume that something is wrong with the vehicle--basically the only thing i can say is that 18 mpg around the city is pretty good compared to some vehicles--more than likely if you have problems the ses light will come on--I work at a dealer so we like to see what kind of gas you use(rec chevron) and also what weight of oil you use(the only reason for oil weights is b/c of fuel mileage). we also check the air fuel alpha(have to use consult-2--do not know if non nissan scan tools can access this info) it is suppose to be at 100% +or- 9% so anywhere between 91% to 109%---do not know if this info is any help to you but I gave it to ya--send me a message if you want to ask any questions--I do not have all the answers but I ll try and find them(I own a 2000 maxima and I get around 17-19 mpg)

 

my 2000 max gets about 18-19 around the city. If I go on a road trip (ie interstate driving) I'll get 22-23.

 

Is it true when you use seafoam white smoke comes out of the exhaust pipe? Thats what i heard.

 

I wouldn't follow the DTE to figure your gas, since it's not accurate. Just record the odometer at the time of fill up and exactly how many gallons it went in the tank by looking at the pump. Write that down, then next time when the gas light comes up, then look at the mileage, and subtract that from the last time you were at the pump and divide it by the gallon you put it in at the time you were at the pump. That should give you the right mpg and compare to the DTE if there are some inaccuracy to the computer. I hope it helps, i know it's sound stupid and corny but perhaps that something you should look at.

 

Surprised no one else has said this. Damn I thought that was the only way to tell your miles per gallon. You dont want to know what my miles per gallon is like right now cus it is -35 degrees .

 

with 85k on the odometer, i would definetely consider changing the fuel filter.

 

I calculate my MPG by taking whats on the odometer and dividing how many gallons it took to fill up. What "FanaticMadMax" said seemed too complicated and didn't yield correct MPG when I just tried his method.

 

Yes, white smoke comes out the tailpipe. A LOT of it.

Seafoam isn't normally used through the gas (though it can be, not sure if it's effective though)
The can has instructions.
Basically, you run the engine (drive it) until it's hot, drive out to some remote area where you can do this, pop the hood with the engine running, remove a large vacuum hose (e.g. the Brake Power Booster--might wanna bring some pliers with you to pull back the hose clamp, and to wiggle the hose off if it's stuck), pour 1/3rd the bottle in there steadily (pouring in fast, but not fast enough that the engine stalls), then shut off the engine. Reinstall the vacuum hose and let the engine sit for 5-10 minutes. Start the engine up and try to use the gas to prevent the engine from stalling. Once the engine can idle fairly stable, put it in gear and drive it GENTLY. Don't get hasty with the accelerator. After about ~3 miles or so I find the exhaust smoke stops, and the engine runs great. If this is the first time you've ever done it and your engine has a decent number of miles on it, you may notice a significant improvement right away (I did).

 

One...winter fuel is bad on mileage. Two, colder air is better for power but worse for mileage. Three, NEVER figure your mileage using the trip computer. It's so far off on mine that I just ignore it. Amazingly, the average speed and time functions work great.

 

Wait, you put it in a vacuum hose? Which hose? What exactly is seafoam? What does it do? I mean, I know it makes your engine run better, but how exactly does it do that?

 

OK, I did it. I noticed a little bit of improvement afterward. Not bad for a five dollar bottle of 'paint thinner'.

 

i beat the bag out of mine and i get like 21, but hey im happy

 

It does it with magic. If you can search, if not go back a couple of pages in the 4th gen forum, they use it like crack over there. I put it in my crankshaft yesterday. It's supposed to eat the nasty carbon build ups and old oil funk. I like it. I did it to my principal's Sebring and she noticed a difference. She also drives alot and could tell the performance boost.

 

I'm getting 20 mpg.....4 months ago I was at 22 mpg

 

Yeah I did it yesterday through vacuum. How did you put it in the crankshaft? The best part is the stares from the people as you drive away with white smoke billowing out of the tailpipe.

 

Change my oil alot and am using MOBIL 1 and running on PLUS gas .
check this : 33 HIGHWAY / 25 Stop and go sideroads

6 speed SE 3.5 2002 ENGINE with 2001 front nose and grill. HID delete
Whats mine magic?
Make sure you reset before you read the MPG.
I tried it a few times to confirm this.
It gets lower if I let the car sit .
It likes to go zoom zoom

 

My auto SE was making an average of 20.1mpg in town. I switched to Mobil 1 Supersyn 5w30 and it went up to 21.3mpg average. I have not changed my driving style. I don't know what was in there before, but it must have sucked.