05nightrider

is it still under warranty? with 18K and just at 3years you might be ok.... anyways.. change the fuel filter.. and if thigns arent better take it in. deff not right

joihan777

Have you stopped by an autoparts store? Some of them will pull trouble codes from the car for free. It may be worth your time! I think it's cheaper than just start replacing stuff (Of course,some things oughttabe replaced anyway).

Do you have a way of reflashing the computer back to stock? Maybe there's a gremlin in the tunes.

nonstopred

i get like 14 now...all around town...drive pretty hard

the winter sometimes i get close to 11.9 because of the ethanol crap, but never lower then that

Somethings got to be wrong unless your driving around in 1st gear at 4k rpm for miles at a time which i dont suspect your doing lol

howarmat

how the hell are you guys getting such low mileage....i drive the **** out of my GT even in the winter i get 17-20.......i thought better gas mileage was one of the reasons to get a sixxer

07 Stang

Is that 17-20 on the highway or in the city? It is clear something is wrong with the OP Mustang. I am currently getting 24+ in the city with some highway miles.

landon.moss

if i drive easy around 55 mph i get 25-30 mpg, but intown with the AC on is horrible mileage...around 18...in the winter i'd get 21 in town using ethanol "crap"[8D]

howarmat

24 on the highway when i made the trip to west virginia a couple weeks ago, but its only 10-20% of my driving normally

chadlet

I had an 06 v6 with about the same mods i have on my GT now and i was getting 18. But for some reason my new 08 GT gets 22-23 all day driving it hard or easy it still gets 22. Not sure why it gets better than my v6 but I LIKE IT

chavalo_nm1

Dude its definetly your headers...........to help you out ill give you my stockers and you give me your JBA's ........

FyouGitive

What are the physics involved in low miles per gallon, that the OP hasn't eliminated in his statements? His drive seems easy. That kind of driving I get a dependable 18-19 mpg; ~ 13 at the drag and autoX tracks; last week a bona fide 22.7 for a 120-mile cruise-controlled 70.2 mph out-and back on I-8.



Weight? Does he have a ton of stuff in his trunK?

Transmission packing up, resisting roll?

Slipping clutch or screwed-up automatic?

Brake pads dragging on the discs (sticky pistons; parking brake not releasing)?

Some ancillary bearings shot (Power steering pump, A/C, alternator) creating drag?

Really fat tires, sticky tread compound, wheel misalignment front or rear? Low tire pressure?

10 mpg is about half what you'd expect (as a minimum); only half the engine is using the fuel efficiently, or the whole engine is working twice as hard as it should have to.

Except for WOT, a dirty air filter doesn't have much influence.

What have I missed?

(edit: Locking gas cap? What kind of neigborhood does he live in? I had a P/U that got very bad mileage until the cops caught a local kid helping himself!)

Still a mystery.