+30.6 showing on the dash. I calculated last 3 tanks. 31.4 30.4 and 31.7 The average being 31.1. Mostly highway driving. I live in the sticks, and commute to a metropolitan area every day. Not bad for winter. should see mid 30's without even trying. Still not up there with most small cars but its worth it!
Now this is closer to the kind of averages I would likely see if I drove mostly on the highway with some city driving and other types mixed in there as well. Now in the summer it may be even better because all my cars as well as everyone I have talked to about it all say their mpg falls during winter when the poor winter blend fuels are used and during the summer it's better. Mine fell around 1-2 mpg at least. It is enough to notice.
My last full tank I averaged 30.7 but I went on a 170 mile round trip to take my girlfriend to an appointment and the speed limits are mostly between 45-60 mph over there and the car seems to get decent mileage at those speeds despite the fact not all or even most of that tank was highway I thought that was pretty good considering it's winter blend fuel. The tank before that was under 27. It seems to stay between 27-29 depending on where I drive etc....and at least a couple mpg higher during the summer and I've gotten as high as just below 37 on an entire tank that was probably 95% highway but I did have to sit in traffic basically at a standstill for around a couple hours or so total and besides that it was all highway. I think if it wasn't for that very slow moving 2 hour stretch it could have gotten up closer to 40 mpg.
I've never went far enough on the highway to use an entire tank 100% highway. I got around 360 miles or so on that tank I think so I'm pretty sure I could hit over 400 miles on a straight all highway run. This cars power and handling and performance per dollar and per the mpg it's capable of is truly amazing. This car is making nearly the power and torque the old fox 5.0s had from the factory in a much lighter car (even more light than the fox). But it gets far better mpg around town and on the highway.
Back in the day it wasn't anything special for a 4 banger turbo to keep up with or outrun the v8s of the time but the ones that did it were getting similar mpg to those v8s if not worse. That's one of the more impressive things about this car imo outside of its handling and fun to drive nature. People say well averaging 30 and getting near 40 on the highway isn't like the greatest some cars do far better (hybrids and such and other small engines with small power) but considering the performance the car has and the fact it has tons of mid range power and torque and what it's capable of I think that mpg is phenomenal. Just my .02
P.S. I did manage over 40 mpg last summer on a straight highway run however it was only around 125 mile trip I wasn't anywhere near the half tank mark yet but I filled back up just to get an idea of what it was capable of on an all highway run. I was pleasantly surprised when I seen it was over 40 mpg. If I remember correctly I used 3.1 gallons over 126 miles of interstate driving I kept it around 70 most of the time there was one small stretch where speed limit dropped to 60 and I dropped my speed to that as well. It came out to 40.6 actually.
I am not stock I have a livernois motorsports 93 octane tune (I noticed a couple mpg increase after I uploaded this tune when i stay out of it anyways.. lol) and I am also running full synthetic oil the royal purple xpr race oil I have the lightest optioned st in which I've taken around another 100 lbs off of that so I'm probably in the low 2600 lbs range without the driver. I also have a muffler and resonator delete so it has a straight piped stock catback as well as a k&n drop in. Idk if any of these things effect mpg significantly or what I don't have any perfect scientific data to show that but I am a believer that every little bit helps and it can all add up to make a difference. I also tried to break the car in the best I could...(didn't go as far as the engine breaking in 101 thread on here) Because fortunately I didn't see that until I was already past that initial 1000 mile mark. But I did change the oil to the stock stuff at 1300 and 3300 miles and around 8000 I went ahead and made the switch to the rp and never looked back. Has anyone else seen results like this? I'm not sure if all that together made any difference at all or these mpg figures are pretty common on the FiST. I've noticed a few like the post above reporting some decent mpg but I've also seen a few claiming not much above mid 20s on mpg averages and consider the stock 33 mpg highway rating to be very generous. I was thinking it was kind of conservative base on what I've seen thus far. I've had the car for 1 year in about 2 months and I'm just under 22k miles and knock on wood haven't had any issues at all thus far. This car is near the top if not at the top of my cars owned list I absolutely love it.....