Im getting only about 17-18 mpg on my maxima and I dont have any mods at all on the car. I dont know what is wrong, I have about 94,000 miles and all I do is highway 80% and 20% city driving during the week.

 

any CEL's? did your MPG noticably drop all of a sudden, or what?

 

im in the same boat.

i get a little better though, but if i get 21mpg on a tank hell will have frozen over.

best ive seen is ~20.5 on a partial tank and very easy highway driving.

 

somethins up i get 25mpg in town give or take and 30+ on the highway. i get over 300miles a tank and i dont drive easy ( i love the sound of my CAI)maybe because its cali spec ?

 

well i have the same problem i get around 22mpg. what is there that i can change to improve MPG....?

-moo

 

i can do 350 miles on a tank, and im barely getting 20mpg, normally 19ish

 

possibilities...
1. the way you drive
2. 02 sensors
3. knock sensor
4. MAP sensor
5. fuel pressure module(regulator)

 

I think maybe its because there is way too much start and stop in your city driving...I get worse, only 16, for mostly short trips less than 2 miles and some highways...and I only get about 300 miles on a single tank for driving like this...but as soon as I get on long interstate trips...I get over 500 mile range for a single tank, a little less than 30 mpg.

 

i get about 280 before the light comes on... depending on how i drive. and that's almost all city and no highway too. i dont drive on the highway very far...just around the wdc area. I know i took a huge hit when i put on the bigger rims. i think its because they weight more, the tires are wider, and i dont have them properly aligned. before i got the rims i think i had like almost 400/tank. it sucks but whatever. i can afford it

then again, our tanks are 18gal. 300 / 18 = 16.6 mpg roughly, ill take 17 though because i floor it on a couple open roads when i can. I envy your 19 =o

 

22 MPG is good, the 4th Gen Max is rated at 21MPG brand new.

 

- clean TB and iacv
- replace air filter
- spark plugs?

some people would advise the fuel filter as well, but i don't know. my mileage has decreased since switching to the 300zx filter. also run some chevron techron in the gas tank. run the car to a 1/4 full and then before you fill up, pour in the techron so it will be better dispersed. change the engine oil after running through the tank with techron in it. you can find it at most auto chain stores.

 

If you dont have any cel's check your tire pressure make sure they are set right..29psi Make sure your air filter is clean, you should change your fuel filter and clean the throttle body. Doesn't hurt to put some good old seamfoam in the gas tank either. I have a 1997 max auto w/199k NO MODS, I still get over 400 guranteed on highway. my light comes on about 425miles.

 

Oh yeah, try a bottle of fuel injection cleaner and see if that helps.

 

Most of us have the "lead-foot" syndrome.. it's a ghost code that is not reported by the ECU and it doesn't set the CEL. Symptoms of the problem typically include a lighter wallet or big gas bills.

17-18 is low. Check for codes - you probably need a new knock sensor.

Depending on the maintenance history of the car, it might be time for a once-over (on everything).

 

Man I just got 867 out of two tanks together....
I do all city driving....
If nothings wrong with your car, then I don't want to know what kind of driving you do around town....
As everyone else has said, check CEL's if you got em... Knock sensor, o2's, plugs are some of the most commen culprits.

 

A quick look on edmunds.com shows a rating 21/28 for city/highway for my 96 GLE...

I get about 23-25mpg usually (80% highway), and top 28mpg on road-trips.

 

wow i only get about 13 and i just changed my knock sensor,an o2 sensor and got new plugs..idn wtf is wrong

 

yeah, i was getting about 16 before replacing my knock sensor. now it's around 20 mpg, mostly city driving.

 

i can go from SLC and coast on fumes into vegas.

 

You guys wont belive me, but I had the same problem and I bought one of those tornadoes for the air systems and sure enough my gas mileage went up and I get better pick up when I drive which in turns means you get a couple more horses, it really works!

 

most people get lower gas mileage in the winter. try switching to different gas. some of them go overboard with the winter additives.

 

knock sensor

 

..............uhh.........................mmmmmmmm ............................ahhhhhhhhhhhhh........ .................................................. ..........................ummm.................... ..........ok

 

No one bothered to ask, how EXACTLY did you calculate your MPG?

 

I have had my Max since new and can get 26 or more on the highway - never took a trip far enough one way to use an entire tank - LA to Vegas or San Fran furthest drive and neither of those use a full tank.

I just got 19 - all city driving on my last tank - 300 miles on the tank - not to fumes.

 

How many gallons did you put in?

 

I used to fill up my tank and get about 300 miles per tank /15 gallon tank = 20mpg. After the tornadoe I got between 345-360 mile per tank /15 gallon tank = about 24 mpg. Another good thing to do is use Chevron gas, it burns alot cleaner. I compared it to a couple of other gas station by cleaning my exhaust pipe tip and then filling my tank with different gas. At the end of the tank I would see how dirty my tip would be. Chevron came out almost spotless, Arco came out the dirtiest (big surprise). Always go with chevron even the lowest grade chevron is better than the top Acro or other cheap gas station.

 

How do you figure it's a 15 gallon tank?(which is wrong) Also You are calculating your mpg totally wrong. It's the amount of miles you've traveled divided by the amount gallons you put back in. Do this a couple of times and you should get a rough estimate of your mpg.

 

Calculating REAL MPG > than 85% of the .org

 

Fixed.

 

I put in 14.5 to 14.8 gallons three times, got about 275, 280 miles off of that. That was filling my tank up to the fullest, and driving until the reserve turned on.
I did get a check engive light, and at the time I checked the codes and it showed that knock sensor might be bad. I also put in gas tank cleaner and then the check engine went away. Did this about three times.

I also dont drive hard at all, I barely go above 70 on the highway, and never accelerate where the rpm's go more than 3500.

 

KS > you .

 

Calculating Your Car's Miles Per Gallon (MPG) Yield


Fill up your car's gas tank all the way.
If your car has a trip odometer, reset it, or record the master odometer mileage.
Drive your car as you normally would, and let your gas tank deplete to at least a half of a tank of gas. (The lower you let your tank go, the better average rating you will get, but don't run out of gas!)
Get to the gas station and fill your tank again.
Record the amount of gas it took to refill the tank.
Record the elapsed trip miles or new odometer mileage.
Calculate
Get the miles traveled from the trip odometer, or subtract the original odometer reading from the new one.

Divide the miles traveled by the amount of gallons it took to refill the tank. The result will be your car's average Miles Per Gallon yield for that driving period.

You can repeat this procedure every time you refill your tank to continue to monitor, and attempt to improve, your gas mileage.

here try this out http://hotrodworks.net/hotrodmath/gas.html

 

I believe I did 291.1 miles and put in 15.3 gallons

 

A full tank got me 420miles at 90mph (that's as high as the cruise control lets you set it) going from philly to Boston. Some of that was city, and some of that was up around 110mph.
I recently changed my fuel filter to a Z filter and changed the plugs and the oil. I am happy with that number, I refused to fill it back up when I had to stop because the CT, MA, NY prices are like 30-50 cents higher than what I pay in S. NJ and at least 25-40 cents higher than what I pay in PA.

 

One thing you are calculating it wrong and also you need adjust your calculations because of your increased wheel size. This will throw off your odometer.

You are a pure genius!

 

I get 29mpg on highway...

'97 SE 5MT with 89k on it.

I get roughly 27 for mixed city/highway. I normally drive pretty fast (accelearte pretty moderately etc.)

A month or so ago I actually wanted to find out if I would save on mileage by driving "easy." My experiment lead to only 22mpg! Meaning that I shifted early to keep rpms low (sub 2500,) and drove no faster then 75mph on the highway for an entire tank of gas (what torture that was.)

I think that driving "easy" gets worse mileage for the simple fact that, for example, at a stop light on a 50mph road... you drive "easy," and you will be accelerating for a good deal of time giving it moderate amounts of fuel through the pedal to get going at all, whereas by driving fast I get into 5th gear close to idle in 1/4 to 1/5 the amount of time. You use up a chunk of gas, but it seems (for me atleast,) to be less then what you use to slowly climb up to speed.

P.S. I routinely get 400mi from a tank of gas, I went 450mi on my last trip to maine.

 

I drive with a slight lead foot. All city miles, and warm up the car 5 minutes before i drive and i average 19.5 MPG. in an auto. I don't see anything wrong with that at all.

I'm going to change out plugs, air filter and give it a gas treatment in the bottle soon to see if that will help me out.