Gas Mileage Problems

[pvtschultz]

I have a 95 3.8 auto, same gas tank and everything with minimal mods and I get about 22 doing the rush hour commutes to school and back, and then when I got home for a weekend, I do 75 the whole 260 miles and I can get between 26-31. I have noticed now with the temperature drop, my car is getting about 2-3 mpg less but that can be because of the air density.

I didn't look at where you were from, but elevation has a lot to do with everything as well. The closer you are to sea level, the more dense the air, the more fuel that goes in for a given RPM. The higher the opposite. But at the same time, the less dense the air, the more you have to push on the gas to get going. But for cruising purposes, you are only really in need of around 50 HP (good guess) to maintain a constant speed. So higher elevations should see better fuel economy. My car also has 130K miles on her now.

I also get between 340-400 miles per tank, regardless.

[ November 04, 2002: Message edited by: pvtschultz ]</p>

[Blizzard96]

Usually I fill up all the way and usually when I refuel, I put in around 12 gallons...13 tops and I usually get AT LEAST 300 miles. The most I got out of a tank was 350+.

Surprisingly, I just replaced my plugs, wires, fuel filter and PCV valve and my gas mileage went down a little. But I think its because this last week I've been driving in more traffic going home (Stupid Halloween) and less on the freeway.

90% of my driving is freeway too...

[ChikNz]

my 01 camaro only gets around 220 :mad:

[Chrisz24]

I am only geting 19-20 MPG around town on my 98 with 19,000 miles, I drive in some serious hills but I was expecting better then that.

Most of the time I get about 290-310 MI

[Only4U]

gas mileage always changes, don't worry about it. if you WOT a whole tank of gas around the city and then drive conservatively around the same conditions on the next tank, you might see 3-4 mpg difference.

[ November 05, 2002: Message edited by: Only4U ]</p>

[Mighty Thor]

One thing though I notice is that when I changed the muffler and induction the gas mileage got better but when I went with colder plugs for the SC the gas mileage went bad.

Say where are you at in SoCal.? I'm from the Riverside area.

[3.4socalbird]

I'm in the Inland Empire. I'm right off of the 10, roughly between the 57 and the 15 freeway, but closer to the 57.

[Casanova]

I just filled up yesterday, and on the 3/4 of a tank I had before that, I got 70 miles. [img]graemlins/crybaby.gif[/img]

[3.4socalbird]

Update:

Two bottles of Fuel Injector Cleaner on about 5 gallons of gas didn't feel like it did much, but i guess it didn't hurt. The fuel filter was changed this past thursday and it feels the same but i thibk it helped out. I had a few more jumps on the throttle lately due to the rain(the rain is tempting to play in when no one is around). I had about 150 miles when i swapped the fuel filter and it looks like i MIGHT see 255 on this tank. I don't feel like pushing it though. Should i maybe look into changing the fuel pump? If so what is a good upgrade but not too expensive? I might start spraying in the future so I'm not sure if i need a better pump. Thanx

Logan

[CARdiac]

<blockquote>quote:</font><hr>Originally posted by 3.4socalbird:
I've got a 1995 Firebird m5 which is getting about 17 mpg on the street and when I drive on the freeway alot it only gets about 18 mpg. I don't floor all over the place either. The car won't see over 2,000 rpm unless I'm hopping on the freeway. The car only has 53,000 miles on it. I just finished changing the O2 sensors and i didn't see any change whatsoever. I can only go about 245 miles on a tank and I've heard of others going over 300. Any help would be appreciated, thanks.<hr></blockquote>


Welcome

How are you calculating the gas mileage? I have a palm pilot program that cals mine. I get 14 mpg in the city and roughly 24 on the highway. I would recommend this.

Fill your tank up to when the pump shuts off the first time.....remember don't overfill. Write down your mileage. Next time you fill up note the miles subract from you previous mileage and divide by the number of gallons you pumped in (again not over filling).

You can create a simple spreadsheet in Excel to track you mileage, fuel consumption, cost per mile and repair/service. I recommend tracking all of that. Looking at one tanks fuel useage is not accurate you leed to look at average useage....and watch for changes......

[CARdiac]

<blockquote>quote:</font><hr>Originally posted by 3.4socalbird:
I'm almost starting to feel better now that I know that I'm not the only one bad mileage but it still sucks to have mileage like that. When they did the 'MSD DIS-4' review, the tested car was getting about 23mpg before the ignition system and about 25mpg after. My auto shop teacher just got a corvette and said he gets about 23mpg. The 2002 Trans Ams claim between 19/26 mpg. Makes me wonder if something is really wrong, but then again I don't know (that's why I came here).<hr></blockquote>

I just calc'd my last mileage....12.9 miiles/gal

The trans Am/Corvette/Z28 all have such good gas mileage b/c they have a but load of low end torque so they are geared to drive on the hwy at very low rpms....thus higher mileage.

[3.4socalbird]

The way I check my mileage is by resetting my trip odometer and then filling the tank up until the pump stops on it's own. I drive around until almost empty (usually about .75-1.25 gallons left), then fill it up again and divide the number of miles travelled by the number of gallons consumed(or the number of gallons it took to fill the tank, same thing). Then I reset my trip odometer and do it again the next tank. I check my mileage after every tank and it averages about 17mpg city/18mpg highway

[DragonFlames]

You guys think you have it bad? Try 130 miles to a full tank of gas last week. Plugs, wires, fuel pump, fuel filter,air filter cleaned and I still got that crappy milage. Im changin O2 sensors tomorrow.