to all you guys who helped me with my milage problem...
hooked it up to the computer, no code problems. knock sensor was ok (though i still may replace it). O2 sensors are all good. and well fuel filter ill still change that. anyway, i reset the computer so that it will "learn" how i drive. i just drove 98 miles and only used a quarter of a tank (22 mpg). not bad..

 

i think i'm like at 20... or 21... but i need to check what is wrong...

how did u check to see what was wrong?

 

man thats good, i was gettin 14 mpg before the reset. well basically the guys on here talked about checkin codes, that wouldnt normally set off the check engine light. so i did in a diagnostic test, and no unusual codes came up. engine checked out fine. but you can reset the system, to tweak certain parts of the engine to your type of driving, hence the "learn" part. umm, i took it to a dealership cause i didnt trust me stuff, and they did it right there in front of me.

 

I got 25mpg my last tank

 

are you sure you measured your MPG right?

just resetting the ECU shouldn't make a drastic change like that.



Just measuring the gas milage by 1/4 or 1/3 of tanks is not accurate.. if you will notice, the gas needle moves quicker on the 1st 1/2 tank than the 2nd..


most accurate way to measure MPG:

-Go to the gas station with more than 1/2 tank empty and fill up to the very top, until the pump cuts off..
-Reset your trip odometer.
-drive around until more than 1/2 tank is empty, then go to the gas station again.
-once again, fill up to the very top, until the pump cuts off..
-note the amount of gasoline you just poured in.
-now, divide the milage shown on your trip odometer, by the amount of gallons of gasoline you just poured in and you get your Miles Per Gallon.


Say my car was 1/2 empty..
i went and filled my tank up to the top.
then i drove until it was 1/2 empty and got 120 miles on my trip odometer.
i went back to the gas station and put in 6 gallons.
120 mi / 6 gal = 20 MPG

 

yo, i was ABOUT to run outside and reset my sh*t in hope i get better gas mileage. I'm like, it cant be that easy to get better gas mileage but i'm diagnose my ecu soon to see if any problems arise.

 

Probably slightly more accurate to just do it per fill-up, instead of waiting until you're at half a tank. There's not really any reason to fill up at the halfway mark. This is, after all, what the tripodometer is for.

 

only 22? i thought mine was bad... (25 mpg/gallon local, 30mpg/hwy) runnin with bad knock and rear O2 =X but rite now my max is in a personal shop gettin it fixed =)

btw wat kinda gas ur running? i still can't believe ur runnin so low.

 

sorry,
i didn't mean that it must be at 1/2 tank.
Just using that as an example

i figure anything at least a 1/2 or more, just to make sure..

 

Resetting the ECU with the screw does not cause it to relearn anything. It only clears any error codes stored in it. This information can be found in any shop manual.

To reset the cars operational parameters and make it relearn you must disconnect the battery for an extended period of time, say overnight or 24 hours. Our ECU's are constantly learning as you drive your vehicle. There is no need to ever clear the operational parameters. This can cause a rough running engine and hard starts while the ECU learns your car over again. It's not recommeneded to do. Refer to chapter 6 in the Haynes manual for more info about resetting the ECU.

 

How many MPG does Nissan rate the 4th Gen?

 

NYCe Maxima is right. That is the best way to get the most accurate mpg (or where i come from, km per Litre). You dont have to wait at half tank or what not. Just fill up gas tank, reset trip odometer drive around as much as u want 1/2, 1/4...... go gas up to find out how many gallons (or litres) of gas you used.

divide the trip odometer reading by the # of gallons (or litres) of gas u used to refill tank the 2nd time around.

 

Heh, I really need to watch my RPMs a bit more. I probably get 14-18 mpg on my daily commute. Basically I take a highway with a bunch lights on it, so its like *stop at light* *accelerate to 80* *stop at light* rinse and repeat 6 times or so. I know I could get good mileage if I wanted to though, on my recent trip to Florida I was getting over 30mpg

 

why does it seem so ranging... we have someone who's gettin' 18 mpg... someone like me with 20.... someone with 22.. and some guy even in the 30... how can I get mine up to the 30 mpg!

 

First time poster, long time reader

I have a 97, 80K all stock, 5 spd with the Check engine light on, and I just filled up....31.4MPG ( about 13 gallons in 410 miles) all back road driving using low octane gas from Sheets. (local ). I do notice I get about 28-29 when using Sunoco gas.

I did check the plugs at 60K, and just put them back in as the looked real good. I did change the fuel filter at 60K though, and noticed a dip in milage before it came back up.

I must be easy on it as I am still on the original brakes on all 4 wheels.

 

that low octane gas may hurt you in the long run.

Read your owner's manual.

 

Yea, I read that...but when gas went way up I switched, and noticed power was down a bit (Still spins the front tires in 2nd gear with the clutch the whole way out) , but @ 80K it runs way better then my wife's Olds at 12K. I pulled the code for the engine light and it is something with the vapor recover system. It goes out when I fill up, comes on at about 3/4 and goes off again when it is near empty. I get no noticable pinging or anything like that and it pulls the hills in western PA in 5th gear with no problems. Doesn't seem to lug. I am keeping an eye and ear open for any problems with the low octane.
What kinds of problems will it cause ?
THANKS

 

Just checked mine and I am getting 24 miles to the gallon.

 

i get 24 mpg and this was my 4th fill up on the car, so far, and i've consistantly gotten 24 - 25 mpg

 

I just did a round trip from philly to bradenton fla.and back.about 2200 miles back and forth on i95, cruising about70 to 80 and calculated about 32 mpg. I bought this maxima in january at 116k miles,its a 96 automatic, it seems to be getting about 22 mpg in the city...the Florida trip is very accurate.