Fuel issue any help please?

[SamuelMach1]

Hey guys I have an 04 mach1 with a 1.7 kb supercharger with 4.10 gears. the car makes 458whp and 540 crank hp I haven't had the car very long and i noticed that is goes through gas like nothing else ive ever seen. I did a calculation and my car had 13,081.1 miles on a full tank. At half a tank i had 13,154.3 and the fuel capacity is 15.7 gal so what i thought was on 7.8 gallons i can get 73 miles which adds up to 9.3 mpg. I baby my car very much its stick and I shift at about 2500 and cruise at 2k i have a lot of hills where im at so i put the car in neutral and coast down hills usually. I'm not a led foot driver by any means. Could there be something wrong with my tune? what should I do? thx
Btw I posted here cause the mach1 section is dead and mach1reg won't approve my account.:shrug:

 

[MalcolmV8]

Before estimating your car used half a tank of gas I'd suggest you fill up, reset your trip meter and drive out a tank of gas. Fill up and divide the miles by the gallons it takes to fill the tank back up. Your gas gauge could be off or a host of other things. Once you get actual mpg numbers lets go from there.

Assuming you are around 9.x mpg though then yes something is way off if you're babying it.

 

[SNK-BITE]

LMAO at your way of figuring out gas mileage. Definitely one of the most scientific ways I have seen it done:dw:oke: Like stated above, do it the right way. Fill it up drive it till a 1/2 tank, fill it up again and use the fuel gallons it takes to fill it again and the miles you have driven to do it the right way. I can tell you right now shifting every gear @ 2500 is going to kill you mileage.

Look in here...


http://www.svtperformance.com/forums/terminator-archive-208/74043-miles-per-tank-new-post.html