Reasons for poor gas mileage?
 

As of late (the past few months) I've noticed that my car has been going through gas rather quickly.

My tires are set to 35psi in the back 34psi in the front. The only time I really push my pedal down is when I'm getting on the freeway, or I'm passing someone. Pushing the gas down for a couple seconds really can't burn that much gas can it?

I'm aware that fuel system cleaning exists.. but I'm not very knowledgeable about them.

What are my options?

Tune-up, change / clean filters.

Yea I'd recommend a full tune up.

To really help figure out what if its something major, or just tune up/ maintenance related, you should do a couple Gas Mileage checks and see what your MPG's are. If your getting low 20's I would call that normal for your car if your doing mixed city, hwy driving.

I noticed about 1.5 mpg or so by changing the air filter. Well inflated tires was a another jump of about .5 mpg for me. Your's sound fine though. The biggest mpg increase for me was driving style. I went from 28 mpg to 33 mpg on my 40 mile one way drive to work. I don't ever floor it to pass or get on the highway. Smooth accelleration and keeping it under 2000 RPM will save a lot of gas. Backing right out of the throttle when going down hills saves tons of fuel. I can wait to get my Grand Prix daily driver so I can "drive" the monte again lol

Like the above posts mention a tune up will likely get you back to where you were

Why don't you tell us your gas mileage so we can see how bad it is (miles on a tank of gas vs gallons to fill it up is close enough if your car doesn't have an AVG MPG reading).

The second question- have you been following the manufacturer's maintenance schedule for changing filters and fluids?

what everyone else says, and do you sit in it alot while it runs, while not driving? thats kills mpg

hell ya, i hit the remote start every morning for just under 10 minutes. im sure that burns it up real fast. im pretty sure your car has a fuel filter,and an air filter. i would change those first. do an oil change. how many miles has it been since you've changed the plugs and wires??? cant remember, change um.

oem ones are suppose to last 100 k, but im not going to wait that long.

i keep my tires at 31,32, not sure if going up to 35 will help you there. it probly makes your ride quality worse.

unless you drive like a grandpa your not going to get the stated 23 city and 30 highway. im sure thats not exact, but you get the point. i dont run the **** out of my car, but i dont go slow either. i get around 24 city/highway. i think thats pretty good.

unless your getting less than 20, i wouldnt be concerned. if it bothers you that bad go get a toyota or something, my g/f's car gets like 32/40 for real. she might get gas every 3 weeks or so. your only problem is that youd be rocking a 1.8 vvti dohc, instead of your 3800. you do the math.

Daily I'm driving about 20-30 miles, and that seems to burn up close to a 1/4 of my tank. It's mostly freeway driving, mixed with some city.

As far as scheduled maintenance, I'm the second owner of my MC I got it around 60k miles I'm @ 86k now. Original owner leased it, I'm really unsure of what he did or didn't do to service the car. The only things I've done routine oil changes, cabin filter, and I swapped out the trans fluid for the dexron 6. I don't floor it either I push it down pretty smoothly.

In the morning I'll also warm the car up for maybe 5 or so minutes with the remote start, and the only sitting with the car running I do is when I'm picking my gf up from work and that's only for a few minutes.

And so basically the picture I'm getting is my car needs:
-tune up
-air/fuel filter
-plugs & wires?

the plugs and wires may run you a little more, i would check the air filter for sure, thats sure to be dirty if its stock, and the sitting for 5 minutes wont help the mpg, it will bring it down a bit, fuel filter could also be a problem but at those miles i dont see it being that big of an issue.

i would check the air filter, does the car pull at all like it needs an alignment? alignment can make mpg worse if it is off but not by too much

Nope, I think those were optional that year :)

That doesn't really help- GM fuel gauges tend to seem to be top heavy- where the top 1/2 of the gauge is like 75% of the tank, and the bottom 1/2 moves quick. But if you're getting 80-120 miles out of a tank, something is seriously wrong- especially highway.

Next time you fill up, zero your trip odometer- then next time you fill up- record the gallons, and the reading on your trip odometer, and figure actual MPG.