Gas Mileage on a 98 Maxima

I have a 98 Maxima with 29,000 miles and it is simply terrible on gas, I mean terrible. My friend also has a 97 and his is terrible on gas as well. Is this common to this generation Maxima? Neither of our cars have any lights on, or problems that we know of .

I fill my car to the brim with Super (93), and 40 miles later the gas guage is already about halfway towards 3/4 a tank. 40 to 50 miles of driving like an old lady on a 1/4 tank is terrible in my opinion. I am really shocked and I am hoping it is something that can be adjusted or fixed to improve it. This is my first Nissan and I have to say that so far I am really disappointed in the workmanship on these cars. I have a laundry list of foolish problems that are common to ALL Maximas and it is a shame because they are not cheap. I have always been a Honda owner and so far this Maxima has done nothing to win me over from buying another Honda. Its too bad. Sorry for the rant, any help on the gas mileage question would be greatly appreciated. :banghead:

Help on your maxima:

If you're going to bitch about it, sell it.

Help on the gas mileage:

That seems to be in par with my 96 Maxima. I average about 400 miles to the tank, or 100 miles to quarter tank with regular highway/city driving. When I took it across country I made upwards of 450 a tank, which was nice.

You could always do a tune up on the car if it hasn't had one recently. Fuel filter, air filter, PCV and stuff. Do you know if the car sat a lot? 29k for a 98 seems pretty good, but if I remember correctly, if gas sits in a tank unused for too long, it can cause problems.

Isn't this website supposed to be for us to 'bitch'?


Yeah the car sat alot but most of the problems related to it sitting have been addressed. Replaced the air filter, fuel regulator, plugs.

I always thought of it as a place to bring topics about cars and discuss them with other people in a forum sort of manner. Whining, on the other hand, is for shrinks. As stated before, if you dont like it - get rid of it.

Anyhow, that's about all i can figure to be wrong with it. Good luck.

Well I am new to owning a Nissan, and I am little suprised at how foolish and common some of the problems the cars have are, especially for a car with such a big fan club.

In regards to the gas mileage, I wonder if it could be an O2 sensor that just has not tripped a light yet.

I figure that cars will always have their foolish problems. I'm sure hondas have theirs too, as do VWs, Mazdas, Toyotas, Bimmers, Mercs, and every brand of domestics. When cost comes before quality to the manufacturers, the consumer is always the one that gets screwed. What can you do?

O2 sensor may be it. Do you know how to test them?

I don't know how to test them, tell me how. I have also been told it could be the Mass Air Flow Sensor as well. I just find it hard to believe that such an expensive part (MAFS) would need to be replaced without showing more serious symptoms. I"E Check engine light, stalling etc.



I did find Bosch & Denso 02 sensors online with free shipping for between $70-$100. Much better than the $149 the dealers want for them.

Heh. i started dictating from the chilton manual, but there are a few steps to perform to do the whole check.

I suggest running to a book store and picking up one of the manuals, either chilton or haynes - or, if you blow all your cash in gas to get to the book store, just breeze it over. Heh.

Though, if you would like all the steps to perform, drop me a PM with your email address and i'll see what I can do.


Yeah, and you can always find parts for tons cheaper than what the dealerships charge for them.

Judging on all the problems I have has so far with this car, the book might be a good investment.

What do you think about my MAFS theory? When those go they usually give other more serious symptoms no?

My Gas Milege Is Horrible Too. I Get About 250 A Tank Which Isn't All That Great. Do You Think Performance Mods Might Help The Gas Millage In The Car. I'm About To Install A Weapon R Intake And Holley Fuel Pump In The Max. Just Wondering How To Improve The Situation Since I'm Going To Be Under The Hood Anyway.

I believe those Mods will no doubt make your gas mileage worse than it is now. Do you currently have any lights on in the car? How many miles and what year is it?

yeah, throwing more oxygen - and a pump to put more fuel, probably won't help things, not that they would drastically make things worse, depending on your driving abilities.

As I think about it, would exhaust mods help things out, since they help increase horse power to the wheels without actually adjusting the air/fuel mix?

Exhaust mods can help & hurt. If the new exhaust has restrictions, it can change how the car runs and effect fuel economy. If it lessens the back pressure it will alsp effect fuel efficiency as well. Anything out side of what the factory recommends can have some effect on gas mileage, be it positive or a negative effect.

Exhaust mods can help & hurt. If the new exhaust has restrictions, it can change how the car runs and effect fuel economy. If it lessens the back pressure it will alsp effect fuel efficiency as well. Anything out side of what the factory recommends can have some effect on gas mileage, be it positive or a negative effect. It really just depends on what you do and how.

My mileage on my 98 5spd is terrible. I think im gettin under 200 a tank. I was able to get the two front o2 sensors off ebay for $120. I hope thats the problem, I already changed oil, air filter, fuel filter, plugs and used BG 44k fuel cleaner, cleaned the TB and cleaned some of the carbon out with sea foam.

My mileage on my 98 5spd is terrible. I think im gettin under 200 a tank. I was able to get the two front o2 sensors off ebay for $120. I hope thats the problem, I already changed oil, air filter, fuel filter, plugs and used BG 44k fuel cleaner, cleaned the TB and cleaned some of the carbon out with sea foam.


Sounds like you are going through what I am going through. Tell me something, when do you plan in putting in the new o2 sensors? Can you let me know if it makes a difference for you? Are they setting off the check engine light? I think we have the same problem, lets try and whip this thing!

I want to do it as soon as possible but its really cold out, it just snowed and now its all slushy. Im not sure when Ill have a chance to put them in. I have no engine check light so maybe the sensors are close to going.

I want to do it as soon as possible but its really cold out, it just snowed and now its all slushy. Im not sure when Ill have a chance to put them in. I have no engine check light so maybe the sensors are close to going.



I was thinking the same thing..I don't think the check engine light always has to be on for them to necessarily be bad. Where I am it is snowing as well so I understand. Be sure to let me know when you change them and how it worked for you.

I did the math today after a fill up, to get the MPG I am currently getting.

I went 228 miles on 15.8 gallons of gas; that is 14.4 MPG. This a vehicle that is supposed to get at least 20 MPG on a bad day. After doing this calculation I now KNOW for a fact there is a major issue with my gas consumption.

I had about an 1/8 of a tank left when I filled up today, the 228 miles was from a full tank of 93. I am guessing I would have got about 250 miles before it was too empty. 250 miles for an 18 gallon tank is really low. I have spoke with many people who say their 4th generation Maxima's get closer to 400 miles per fill up.

Yeah, 400 miles per fill up was what I was saying earlier.

Perhaps it's a throttle position sensor issue, like i've been having. I've noticed a bit of a fuel drop since that's started to go. Have you checked that?