drakefamily2

I get 25 mpg on the road, v6.

Chromeshadow

I don't know how yours should compare with an 2000 3.8, I bought mine new in 2000, and drove it for about 15K miles. It got about 18 in town and 25 on the highway. I added an under drive pulley and advanced the timing by rotating the crank sensor. I run 89 octane when it's over 90 degrees to keep it from knocking.
I added a MAC cold air kit with a K&N, and dual exhaust from a V8 with an H pipe. Mileage average went up to 27 mpg, got 31.9 driving through Iowa at 80 mph. It has 187,000 miles now, still gets 29 mpg on the highway. I'd change the plugs, make sure they are platinum, gap them with a wire gage not a feeler gage. I'd check each wheel to make sure nothing is binding, they should rotate easily when you jack the car up. Keep the air cleaner clean, check the air intake to make sure all of it is clean. A Mustang is a light aerodynamic car, there is no reason not to get 25 mpg or more on the highway, even driving fairly hard.

Tanner05

I have a manual V6 and I get about 17 in the city.
I did start getting much better gas mileage after I put in a new air filter, so hopefully that helps you out a little.
On the highway, I usually get about 27-28.

rls82959

That's the first thing I would check OP. Dirty air filter.
My numbers are darn near identical to Tanners.

bakerjd

He's driving mostly city so info regarding long trips/highway driving isn't going to help much. I know that you're trying to help but the driving habits you mentioned have nothing to do with his situtation.

kput

Alright well I replaced fuel filter yesterday, as I stated,
and checked out my air filter. Looks brand new.

So still a bit curious as to why people with the same car as me are getting better mileage.

Oh,
one thing. I filled up today, after replacing the fuel filter.
and my gas gague read 1/4 tank. Slowly it went up and now it's near full (although not completely there).
Any idea why it was reading wrong?

FordService

kput,

Driving habits play a large part, but I know most dealerships have a promotion on a Fuel Saver Package with an oil change, where they check multiple known causes of lower fuel efficiency. You might consider having your oxygen sensor checked as well. As for your gas gauge, if I'm on an incline mine has been off, which may be your issue, or it could be that your gauge is starting to read incorrectly.

~Natasha

kput

Ahh sweet, I'll have to swing by the dealership and have them check it out!

As for the gague, I figure it was just from me de-pressurizing my gas lines and such to switch out the fuel filter. It's registering correctly now.

Bitter

My '06 4.0L is a daily driver, and I'll grant you that 90% of my commute is highway, but I'm getting a little over 30MPG.

kput

Aaaaarg, see, something must be wrong!