Any input would help why for the last few tank fulls i only been getting ~225 miles for 15 gallons (approx 15 mpg). I have ~23k miles on the car, commute is approx 10 miles each way on highway/local streets and i drive everyday. is it the chemicals gas station dump into the car in the winter, tune-up time? (car is totally stock), something not set right in the car, or my 18 inch rims?

even in the past, i would rarely ever get 20 mpg in the summer. thanks in advance for any reason why this car gets such crummy mileage.

 

I get the same MPG

 

city driving sucks on these cars. I've seen 17-19 mpg in my car. I'm also an aggresive driver sometimes...

 

I have a 2k1 with 22k miles. I get the same MPG.. I only notice a change when I start driving a lot of highway miles. I took it to the dealer but they didn't see any problems.

 

yeah, it sucks...combine city driving, with a heavy foot, and lots of cold idling in the morning, and i've gotten as low as 160 miles between fill-ups...i'm on synthetic oil to boot. go figure. i'm still around 25mpg on the highway, so i figure it's just normal.

if you do decided to take it to the dealer, bring receipts of at least a couple of fillups, and remember to fill up with 93 octane. good luck!

 

i wouldn't worry if i were you. i average 11-15 when i'm in the city. right now i'm in boston, drove up from NYC yesteray morning and i averaged about 25mpg. i was worried, but yesterday's trip just showed me how much gas gets wasted in daily stop and go nyc traffic. when i fill up, i usually get 225 DTE but coming up here to boston, it went up to 385. right now i have 275 on the tank and i still have about 110 DTE.

and an added reason for you noticing is the gsaoline they use for the winter, and on top of the fact it being winter, most gas mileage is bad due to the extreme temperatures. give it time, it will improve.

OR, you have a bad O2 sensor?? i know on my 91 max i was getting 110 miles on the tank, replaced the O2 sensor and it jumped to 325.

hope this helps you understand your problems.

 

hideous!
I used to get between 280 and 310 miles out of a tank on my '01 SE 5-speed in mixed city/back roads driving; since I did the ignition advance I now consistently get between 295 to 330 out of a tank -got 345 miles out of my last fill-up.

You guys should really consider the timing advance mod...it will really help in the kind of driving you're doing -specially with gas at 2+ bucks

 

I just bought my 2001 SE (10K miles) last week and I've been disappointed with gas efficiency, too. How much does a timing advance mod cost?

 

The magic number seems to be around
$40-$50, about a 30 minute job.

 

Hi All Fellow Frustrated Gas Enthusiasts,
Here's my 2 cents. Took delivery of my 03 SE in December (Great month to buy cars buy the way... really wacked em').. anyway, I was getting 16 mpg regardless of how I drove. I'm at 5K now (breaking in helped) and I have done extensive testing on driving habit ranges, but I'll give you the baby... not the labor. Max responds very well when it's asked to perform (that's why we bought them), but nothing is free in this world or Max's. Try running an entire tank driving her very conservative. Easy excelleration etc. Getting on the highway, work the speed up evenly and set the cruise for 70mph (I know it's tough to resist the urge to blow away these yungun's in thier VW's). Get them next time. Under these conditions I got 22-24 mpg (26.5 in an all highway stretch). Consider the cost of playing "entertainment". The cost of the extra fuel is cheap, "fun", entertainment. It costs me $50 to ski all day, but only about $20 extra to drive spirited for a day. I figure I'm saving money! I've accepted the fact that this is not a 4 banger sentra... Enjoy!

 

320-330 Miles to the tank for me, but I do alot of highway driving.

 

I have a 2k2 6spd maxima and I too have been getting poor gas mileage. Around 15 - 18 in the city. Hasn't always been like this. Anyway I dyno'd my car a few weeks ago and got hooked up to the wideband O2 sensor. I found out that my car is running way too rich. My air / fuel ratio is around 11/11.5 to 1. Absolutely absurd. Anyway I ordered the Apexi SAPC II last week to help me with fuel mgmt. After this fine device is installed I will surely see better gas mileage and more HP.

BTW - I've seen some AF graphs of a few other Maximas that have been running rich too. I haven't seen anybody with an AF ratio as bad as mine however there mixture was still rich. You might want to investigate this if you're getting bad gas mileage.

 

2001 AE Auto fully loaded, app 20k miles. Getting 15 - 16mpg - 95 % city driving. On a trip to the coast, I got 26.5 mpg - 60% highway, cruising and 40 % small town, twisty, 2 lane roads. Most highway driving, I get 26 - 28 mpg. BTW, I got the timing advance and I'm seeing .5 - 1 mpg increase.

 

since you guys cant search, if you only drive 10 miles, its not enough to warm up the emissions. You will be running rich for the first 12-15 mins. All newer v6 cars do this. the Honda Accord V6 gets about 16 mpg for the first 15 mins.. if all you ever drive is 15 mins away, its going to be horrible.

 

Thanks for the tip however being aware of this already, I drove a lot farther than 10 miles before I dyno'd my car. Actually, I drove my car for a good hour or so prior to being strapped to the dyno. The engine was warmed up and I still got a sh**ty AF ratio as indicated by the wide band O2 sensor. Also I've gone on several road trips and I only manage to get about 21 - 23 MPG on the highway which is absolutely absurd.

 

I drive about 15-20 miles to work every day and 15-20 back home.
Seem to stay around 23.8-24.4 according to the computer -- i just got back a couple weeks ago from a 360 mile highway trip to Arkansas and the comp said 29.9, and 30.1 on the return trip. I think the worst I've seen so far is 20.8 if i race every light. I run exxon/mobil 93 octane and occasionally Chevron or Citgo.

From a tech point of view, wouldnt increasing the intake flow and the exhaust flow help MPG instead of hurting it? Or does the ECM need to be reprogrammed/pb'ed to take advantage of the new AFR?

-- Adam
2k2 SE/Icelandic Pearl
35% llumar, V1/Clear corners, FSTB, intake coming soon (tax refunds rule..)

 

The trip computer mileage is inaccurate - it overstates it by 3 to 5 mpg - so in reality you are getting about 19 or 20 mpg during the commute.
Best way to compute mileage is to calculate distance between fillups and the amount of gas you just filled up.

 

I was speaking in general terms.. there are certainly plenty of cases of bad MAFs and O2s to warrant some further investigation.

 

No problem. Thanks to members' post(s) in past, I first thing I checked was my MAF senser and 02 sensers. I'm actually on my second MAF which is only 3 months old. The dealer checked all my O2 sensers and they're fine. I haven't seen to many people bring up the A/F ratio scenario in the past so I figured I'd post it. At least in my case, it seems to be the be the root of my problems. Special thanks to Studman for sharing his experience with me.