Burned 1/2 tank in 65 miles????

[NVMYPWR]

4000 miles on the car

Installed all this at 2500 miles:
DUB 2.80" SC Pulley System
Gatorback SC Belt 4080735
NGK TR6 Copper Spark Plugs - gap to .040"
9" S&B Power Stack Intake Unit
170 Degree Thermostat
Bassani Mid-Length Ceramic Coated Headers
Bassani X-Pipe w/ Cats and Cat-Back System
Accufab Single Blade Throttle Body & Intake Plenum

Everything has been running great.

A few days ago I put in a few gallons of Mobil 1 99octane before filling up with 93.

I decided to take my Cobra to work today (140 mile round trip) because it was nice and a buddy of mine that had just gotten rid of his vette, is looking into getting an 03 Cobra. When I left for work I had just over 3/4 of a tank.

On my way home it was at the 1/2 tank mark but by the time I'm within 10 miles of getting home, I notice my low fuel gauge come on and every minute I could literally see the gauge go down farther. I almost thought I was slowly leaking gas.

I finally got to the gas station and didn't notice anything dripping. I opened the hood. Everything looked okay. Exhaust smelled normal and so did under the hood.

The last couple of days the gas needle seemed to have taken its time to get to the 3/4 mark. I thought that 99 must have increased my gas mileage because it moved so slow.

So do you think the needle was just catching up to where it was supposed to be the last half of a tank? Anyone else notice this?

 

[03Sssnake]

sending unit? I wouldn't put too much faith into the stock fuel gauge...I always get 115-120 to the 1st quarter tank, then by the time I hit the have tank mark I am between 170-190 miles :shrug: With mixed HWY/CITY usually see 220-240...

 

[stangfan]

My guage reads exactly how you described. It always has...

I get about 125 miles to the first 1/2 tank (mostly city driving). By the time my guage gets to 1/4 tank I only have about 150 miles???

 

[03DOHC]

The gas gauge is not linear. I filled up last week at a hair under 1/2 tank and I put in 10 gallons.

 

[maoun]

it's pretty inaccurate

 

[NVMYPWR]

Well the gas gauge SUCKS then...but I feel better since it seems to be normal. Thanks guys.

 

[flyn high again]

My gauge is the same. It takes a lot longer to go from full to 1/2 than it does to go from 1/2 to empty. Stupid gauges...

 

[03_Sonic Blur]

It's absurd to call them guages. Glorified idiot lights.

 

[Friendchicken]

the guage should show the halfway mark as a 1/4 tank. Takes a while to get from full to half, but half to 0 takes no time at all.

 

[ridethelighteni]

I don't think I have ever owned a car with an accurate gas guage - always get more on the first half than the second, but the Cobra takes the cake.

This is without a doubt the most inaccurate guage I have ever seen - if you are on the highway or will be in heavy traffic, don't do it with only half a tank on the guage, cause half is more like a quarter.

 

[mike79]

I always get 75 miles to the first quarter of a tank, but never more then 175 to a tank. Not as bad as my 89 Thunderbird though. That thing would blow through more then half a tank, while the gauge still was sitting above 3/4 of a tank!

 

[wjfawb0]

I can go nearly 80 miles before the needle falls below full when driving the interstate in my Cobra. It drops like a rock after that.

The reserve on my 02 GT was pretty good, though. I always had at least 60 more miles and around two gallons of gas when the low gas light came on. I just pay attention to how much gas I can put in after the light comes on. If I only put in aroun 14 gallons then I know I had around 1.7 gallons left to go.

-Jason

 

[03BlownSnake]

actually, I disagree with all of you guys
The fuel level gauge is probably the most accurate gauge in the car. trust me on that. If you ever taken a look at your fuel tank, you will notice its shape. its not a perfectly squared box, so from full to about half, it will take much longer time to get to half then from half to empty due to its shape. Also on the passenger side, where the filler neck goes in the tank, its taller then the rest of the tank, so it would have to use up all that gas (aprox 3 gal) before the needle actually starts dropping.
So actually, I would blame the fuel tank for the gauge readings.

 

[loose nut]

DITTO on my gauge...exactly as above, non-linear.
But once you get used to it its not a big deal. It kinda makes me feel bad-a$$ having a fuel gauge that moves as fast as my tach. :coolman:

 

[wjfawb0]

Yeah, I am thinking about the personalized plate "GAS HOG". It is probably already taken though.

-Jason

 

[coleman]

read my original thread regarding my dis-pleasure with the stock gas gauge :kaboom:

http://www.svtperformance.com/forums/showthread.php?s=&threadid=20972&highlight=gas+gauge

 

[351MachOne]

Happens to me too... I always think im going to get pretty darn good mileage, but my tank ends up with the bottom dropping out of it =)...


It sucks real bad...

 

[FX-Man]

Boost guage go up.....gas guage go down.....at about the same rate.

 

[saadcobra]

more boost more fuel consume

 

[caveman6666]

Originally posted by 03BlownSnake
actually, I disagree with all of you guys
The fuel level gauge is probably the most accurate gauge in the car. trust me on that. If you ever taken a look at your fuel tank, you will notice its shape. its not a perfectly squared box, so from full to about half, it will take much longer time to get to half then from half to empty due to its shape. Also on the passenger side, where the filler neck goes in the tank, its taller then the rest of the tank, so it would have to use up all that gas (aprox 3 gal) before the needle actually starts dropping.
So actually, I would blame the fuel tank for the gauge readings.

It's also the float properties. A full tank brings the float fully up, but the gas level has to drop below the BOTTOM of the float before the gauge will begin to go down. This is the reason you can go eighty miles without the gauge moving.