[Bullitt95]

There would have to be one hell of a leak for him to get only 118 miles per tank and I'm sure he'd smell a leak that big.
I'm still leaning towards the original 16 year old O2 sensors being the culprits.

[ryanw]

Hey since were all giving our miles per gallon , I'm getting 13-14 mpg
I hope that helps th op out.....lmfao j/k

Ya I'd replace the o2s

[Dan_T_Mustang]

I just noticed today that my tempurature gauge takes REALLY long after I start driving to move up a bit into the "normal" part of the gauge, and even after that it doesn't go up as much as it use to, am I right to suspect my thermostat is stuck open? That could be a culprit for fuel economy as well correct? But I'm planning to do 02 sensors soon too, doesn't hurt. And the fuel injector cleaner someone mentioned.

[MANZO MUSTANG]

I averaged 14.5 on 13.5 gallons of 91 octane.

[dcam503]

wow you guys are funny, glad to entertain. I'm sorry my car skillz are so rusty, i have been riding sportbikes for years and forgot about all the different electronics and parts to a car motor. that being said, i don't know what your issue is. bullit has a point about the leak, i just say that because i have personally had it happen to me with my 99 stang. replace that sensor and see if that works. i didn't realise these had such bad mpg to begin with so thats why i was stating mine.

[Bullitt95]

Originally Posted by Dan_T_Mustang I just noticed today that my tempurature gauge takes REALLY long after I start driving to move up a bit into the "normal" part of the gauge, and even after that it doesn't go up as much as it use to, am I right to suspect my thermostat is stuck open?

Not really. Don't forget it's winter now so the engine will take longer to warm up and it's likely the gauge readings will stay lower too. That's normal. If you want your engine to warm up faster, you could try blocking off part of the grill with silver foil.
Since everyone else is having a "mpg party" I'm also going to join in; 15-16mpg city and 20-21mpg highway (75mph).

[95project]

If i get 12 mpg in mine i would feel pretty damn proud...bet im closer to 10...but who gives a shit, its a mustang. they were not designed for good mileage unless you go with the V6. They made the v6 for girls and for people who want to buy the most pointless combination of engine and car ever made (I'll withdraw this point for the 2012 , 305 HP v6 i guess...).

2 things you almost HAVE to accept when you start modding, crappier gas mileage, and more emissions...its just how it is. Anything over 12mpg i consider good for a 15+ year old sports car.