Horrible Gas Milage!!

:bang: This has been going on for a few weeks now. I can't think of anything that it could be. To start, I have a 95 GT with 30,000 on the stock shortblock, it has Edelbrock heads, Saleen intake, 70mm throttlebody, 73mm C&L mass air and 30# injectors. I am only getting 80 miles to the tank of gas. That roughly equals out to 6 miles per gallon!!! It used to get over 200 miles to the tank, then all of the sudden this happend. I need help! I did not change anything to cause this, nor did any codes pop up when I tested it. I'm not leaking fuel and my air/fuel gauge seems like everything is normal. If anyone has ANY suggestions please help, I will do anything at this point, THANKS.
 
I think someone is taking the gas from your tank.That is the only was short of leaking that your car is getting 6 miles to the gallon with out spitting out fuel from the tell pipes and blowing black smoke like a mack truck.
 
i think tanks get better milage than that. i agree with sub - you might have a crack in your tank or mischievious roommates or something. that is insane. i dont think your milage could be so poor, even if you drove around at WOT non stop.
 
milage

ya , i think some thing is missing here,my 85 454 suburban with a holly 650 gets better milage pulling a horse trailer...it would be running lousy if it were using that much gas..check for leaks in high evaporation areas..and don't smoke around it!
 
get a locking gas cap and see if that helps :shrug:

i had someone pull their car up to mine and siphon my tank directly into theirs. i was only home for 2 hours too, and it was right outside my window. if only i wasnt in the shower and saw them.... what i wouldnt give :bang:
 
I remember reading somewhere that if you don't get spark to a cylinder or 2 you could get really bad mileage, and depending on which cylinder, could be hard to detect. You are supposed to drive around, and check the plugs after for wetness/gas smell. I personally think I would know if I'm running on 7 or fewer cylinders, but who knows? :shrug:
 
check your plugs and make sure there aren't any closed up, those will hurt mileage a lot. but you should feel it miss though if you have close plugs.
 
Could your speedometer be off ? Check your tire pressure and run it on the high side (watch your tire wear in the middle). Get a friend to follow you and see if you are putting out rich fumes / black smoke. Avoid drive-thrus and extended idling. Every little bit helps.
 
Check the codes. Autozone will do it for free. Post the results & we will try to get you steered in the correct direction.