Nuke

Yes, slower. As I stated earlier, the higher the cruising revs, the worse the fuel mileage. I've collected a lot of data on a lot of vehicles; the Stang included; based on my numerous 400+ mile 1 way trips (typically every 2 weeks) over the years. Once the 4.6L (and most engines) get over about 1600 RPMs, fuel mileage begins to drop.

Jas5

i dont count since I have a supercharger but i'm getting terrible gas mileage. Probably around 15 mpg in city, I only get on it twice a day or so. I look at the needle and think "uhhh wasn't that just way fuller 2 days ago"

edit: if i cared about gas mileage i would've gotten an RSX-S (almost got one with a-spec package!). you gotta pay to play

07gtdude

I got about 20 mpg consistently when I had my 07 GT. About 65/35 hwy to city. Manual w/ 3.55s and I drove it like I stole it every day

magiusavvail

I've been doing a lot of city driving these past couple of days. I filled up today around 1ish and put 37 miles on the car running around the city. I am now a quarter of a tank less full. It's really weird. I'm just not used to this kind of guzzling. xD

According to the digital read-out, I'm getting 13mpg in the city, 14.6 if I'm going down a long stretch at 40.

ffk_pennywise

I do about 70% highway, 30% city. 3.55 gears, manual, and the mods listed below. I drive very "spirited" and average 20.7mpg on 87 octane. I got 22mpg before headers and cams.

iamgone

I have an 06GT auto with 3:31s and I get 19-20 with a mix of city/highway. I calculated manually early on and my onboard is within 1 or 2 tenths. If you bought ore-owned, don't forget to reset the onboard system. It will. Still have data from the previous owner's driving habits.

iamgone

Pre-owned, not ore-owned. Dang auto spell correct.

Bruno's 06

GT 06 Manual, 3.55's, 1st 200 miles since I bought it, giving lots of different family members rides and the computer is showing 18.7 mpg.

bronxbill

07 GT manual; has cat backs and Ford racing muffler; no CAI or tune. I get a consistent 20-21 around town and about 26 on the highway if I stay at around 65.

Nuke

That's part of the problem; stop using the on-board for getting a handle on your true fuel mileage. You have to hand calculate. The on-board is good for relative values but not accurate ones, at least on about 80% or more of the S197's.

Also, if the previous owner changed gears or tire OD without adjusting the PCM via a tuner or the dealership, then your on-board and speedometer will both be off.