Horrible Gas Mileage

[stevensolds]

Guys,

I know the cold weatehr has something to do with the gas, but even in the summer i ONLY get 12-13 mpg. Its very bad and I can't stand it especially when i put premium 93 in. I dont drive to school anymore, i hardly even drive the car anymore because of this it really ticks me off. I replaced my air filter a while back and that was a B*TCH to get off. Cut my hand up several times. My muffler upgrade didnt do crap, as that wasnt what i wanted at the time anyway, i wanted better sound. Maybe a Y-pipe will help?

How do i go about cleaning the MAF or would it even be possible for me to do it? I am not mechanically inclined at ALL. About all i can do is replace an air filter. I hate how this dumb broad before me treated this car, i really hate it.

I also want to go about doing the airbox mod that you all have been talking about, if its even at all possible for a 1995 model. I wish this was a 97 or 98, as there are vast improvements over the 1995 model year in just about ever aspect.

Your help is greatly appreciated. This car has been a money pit. I have put $5000+ into this car for the time period 6 months I have owned it. Whilst it is a great car and I love it when it runs right, but after having just paid my $1600 insurance bill which is only good until july, things are getting tough. Owning a car is a big responsibilty for a 16 year old like myself and I do have a job on the weekends and after school , along with a side job of repairing computers (which is my best cash flow), but I certainly hate to see it get wasted by something that could probably easily be cured. I am not whining about the money issue right now, I just want better gas mileage. The aurora will just sit its beautiful butt in the garage until I can do something to make the mileage better.

Thanks.

[Aurora40]

I don't see why a different y-pipe would help your economy. What kind of driving do you do? Even the sippiest engine will get bad economy if the car isn't moving.

The MAF sensor is not cleanable, it would likely just be ruined. If there is debris on the screen, you could pick that off, but that would be a sign that something's wrong with your air filter or air box.

Have you changed the plugs and wires? I would inspect the plugs to see if they tell you anything. Especially if one plug looks much worse or much better than the rest.

Lastly, have you tried driving easily? Try driving the car gently for a tankful. Keep the DIC on instant mileage and pay attention to it. Whatever speed you are at, try to back off the pedal and increase the instant mileage right up to where your speed stops staying constant. Try to get the most economy you can for a speed. If this cures it, then you know the problem.

[stevensolds]

I changed the plugs AND wires less than 1k ago. In 6 months i only put a little over 2,000 miles on the car.

i hardly drive and when i do i pass everyone in sight. i do not drive like a maniac, and i am not wreckless. I like to get in front of slow people and rice burners, and last i like to hear that sexy moan the V8 makes when you bury the tach.

One time i blew through a whole tank of pedal-to-the-metal driving. Needless to say, i only got about 90 miles of that tankful. When i first got the car after spending 4k in repairs and having it sit in the shop for 2 weeks, i was getting anxious and wanted to drive it. I floored it out of every stop light there for a while, but i stopped being an idiot later on. I doubt it hurts the motor, but it certainly hurts fuel economy.

Sigh, i have been trying to drive nice and easy on it, but i do bury the tach here and there, but only when im already moving. I try to accelerate slow out of stoplights, but then again i try to go a little bit faster than most cars will. If theres one thing i hate the most, is when people will take off so darn SLOW out of a green light, and it holds the hold line of traffic up. One time i was the first at a green light, with a PILE of traffic behind me, i was out of there and gone in probably 10 seconds and i could look back and see absolutely no one in my mirror. i laughed my arse off

[JimW]

Its been extremely cold, and the amount of fuel required in the extreme cold is incredible. The car is working harder all the way, idle time is increase, there is a drain on the cars resources in order to warm up the inside, it takes a lot to get the car going initially in the deep freeze, all of these factors are to blame with fuel economy.

I saw (mixed driving) 15L/100km, which even after the conversion is actually 15 mpg. Now my last tank, I let it get down to about 1/4 tank used, and the DIC read 21L/100kms

Its the way things go in the winter. I;m the kinda driver that will putter along at 1900 RPM and 45-50mph (80kph) but once in a while I need to see the tach scream to 5000 RPM (for my own sanity, and to know that I can ha!)

Sweat it out for the winter, and your mpgs will come back. Save the mods til the spring.

[stevensolds]

Ill really bury it at Carlisle Jim, haha. Jim, incase u havent read that thread, i already registered my car for the All-GM nationals, its a go hehe. 2 people, and my aurora. CANT WAIT

I cant be speeding aruond here though in the winter, i was slipping and sliding, almost slammed the car once or twice. Cant do that.

Oh also i have a bad habit of revving the motor in park so everyone can hear it roar. I love to hear it. It sounds great. Vroom Vroooooooooooom and the pop-pop-pop that exhaust makes hehe.

[JimW]

Yeah, that will kill the mileage...lol

[stevensolds]

Jim did you see any improvement in performance or gas mileage with the Y-pipe? The stock pipe is starting to belittle me, i need more performance and more sound. Your interior sounds really nice and loud, mine is too but i dont get the sweet sound effects. When i floor it you can really hear the mufflers kickin and when i let off you hear VROOOOOOOOOOOM as it winds down the RPMs, its sweet but its missing something. know what i mean?

Oh btw i know how hard the cold is on the motor. I try not to drive it in this nasty weather but if i do, i let it warm up before moving it or kicking it in the arse

[erw38]

Stephen,

what I would try is

1) Fuel injector cleaner added to gas tank at fill up
2) Fuel Filter
3) oxygen sensors

When you run the engine, smell to see if you can make out a 'wet' or 'moist' exhaust smell. If you can, chances are you may need new oxygen sensors. The 95 aurora has 2 of them. A mechanic can do a compression test for you (my mechanic will do it for $35 and then apply that to whatever procedure I have him do. Start with #1 and then progress down the chain.

If I were you, I would hold off on the air box mod because it actually decreases mileage (with my experience) in around town driving. There are no improvements for gas milege untill you do a lot of highway driving.

I used to get about 17 mpg pre-mod and 15-16 post mod. Thhen after I 'regutted' the airbox it didn't seem to help. After a few fill up I noticed my mpg improving somewhat.

I have also tried the 'berrymans b-12' which has helped.

**edit**

Just to let you know, I am averaging 20 mpg (its on 1/4 of a tank) on my last fill up with mostly city driving (but there where a few highway drives of 25-30 miles roundtrip).

[stevensolds]

I have a new fuel filter and been adding gas stuff. dont help. thanks though. i will just replace the oxygen sensors i guess.

[kobalt]

Most fuel injector cleaners don't work very well. But one called BG44K does. Its concentrated techron shops use this stuff in their fuel injection cleaning services. It's not cheap ($20 or so a can) but worked wonders for the Maxima. You can't really get it at stores. I picked mine up on ebay, but Nissan delers also sell it.

[stevensolds]

Thanks Kobalt, for 20 bucksi t might be worth it. I will check it out around here and on ebay.

[Custom88]

check out sea foam too. put it in your gas tank with about 1/4 tank left. it works really well from what i've noticed.

Your horrible gas mileage is probably just from having a lead foot. I know when I used to drive the bonneville with spirtied drivign I would only get around 20 MPG but when I drove conservative I got 29 or so MPG. Try to resist going over 2,500 RPM for atleast half a tank and see what your gas mileage is then. Albeit it'll be a hell of a lot better. i can't wait until summer to see my gas mileage ratings. If I'm getting 25.5 MPG in the winter I can only imagine what I'll get in the summer.

[stevensolds]

I cant drive below 2500 rpm, not possible. Under 4500 maybe lol

[Custom88]

stevensolds said:

I cant drive below 2500 rpm, not possible. Under 4500 maybe lol

I think you just answered your own question of why you get such bad gas mileage then.

[stevensolds]

i have too much adrenaline when driving and when other motorists piss me off ,i will go out of my way to pass them. i pass everyone. i hate slow people and i very rarely stay in the right lane -- left lane is my spot.

[Marc]

I do a lot of short distance driving (under one mile). My
2001 4.0 doesn't really warm up under those conditions.
Gas mileage is around 11 mpg then. But when I can
drive it for about 15 miles in in light traffic, it'll get about
18 mpg.


________________

GM!!! BRING BACK OLDS!!!

[stevensolds]

Thats the worst kind of driving you can do. Sometimes even if i have to go very short, i will take a long way home or drive around for nothing so it equals 10 or 15 miles. But thats just me. I will get 8mpg if I do one or 2 mile trips, according to the DIC.

Today i went out about 20 miles i pressed the gas as lightly as i could. Gauge stayed on full where it was 2 days ago. Im gonna try this the whole tank, maybe its just my driving. Thanks everyone

[Letitroll98]

Look at the picture on the bottom of Steven's post. 5500rpm, 117mph, is that right? I assume we have a lockup torque converter in the 4T80E? Is the car in overdrive? Is the tranny slipping? I don't know for sure because I was looking at the road, not taking a picture of the dash, but I believe I ran around 120 at something in the 4000rpm, maybe a little higher can't be certain. Feedback guys?

[stevensolds]

pedal floored do you do that?

[Marc]

That speed and RPM level together would mean that
the trans is in 3rd gear.


________________

GM!!! BRING BACK OLDS!!!

[Aurora40]

The lockup only engages when you are cruising. If you press the pedal down it will disengage and allow the torque convertor to work.

[Letitroll98]

Marc said:

That speed and RPM level together would mean that
the trans is in 3rd gear.

Aurora40 said:

The lockup only engages when you are cruising. If you press the pedal down it will disengage and allow the torque convertor to work.

Thanks guys, I knew someone would make sense of it. I thought it was in 3rd gear with those readings, but I assumed it was because Steven was running his car in 3rd or something was wrong with the tranny. I see that the problem with low gas milage is in the linkage between Stevens brain and his right foot. ;D (Sorry Steven, it's true)

So then I ran 120mph in cruise mode? I love this car.

[omegaic]

Now we just need a picture of someone hitting the speed limiter. A professional driver on a closed course preferably!

[kobalt]

I'll see what I can do..ehm stop by the local track on the way back from school

[stevensolds]

Letitroll98 said:

Thanks guys, I knew someone would make sense of it. I thought it was in 3rd gear with those readings, but I assumed it was because Steven was running his car in 3rd or something was wrong with the tranny. I see that the problem with low gas milage is in the linkage between Stevens brain and his right foot. ;D (Sorry Steven, it's true)

So then I ran 120mph in cruise mode? I love this car.

Ah, letitroll I like to keep my engine free of carbon buildup It is good to depress the accelerator to the floor every week. While what i do may be excessive, and that is not why i did it (dont ask me why), I am a good driver and i am not wreckless. I simply pick my spots where to do the crazy stuff, and execute it with caution.