13 city, 25 highway. When I first got her it averaged about 11 city and highway but that was 6000 miles ago. Just give it time to improve and don't worry about it.

 

also you need to use good driving habits. low rpm shifts, light use of the gas and such. I have talked to some people that thing because it says x amount on the window sticker they should be able to drive it any way they want and get those numbers. This is simply not the case.

 

= BORING!

But I agree that you shouldnt expect to have fun AND get the mpg stated on the sticker.

 

very boring

but if you want mpg and not smilage you know what to do

 

He said he got 137mi on a tank. That's not related to the computer at all.

 

I'm averaging 15.8 so far and I'm about to hit 500 miles......smiling for every one of them too.

 

I got 20+ from day 1. The car had 4 miles on it when I took delivery ( so i bought it new of course). There's something not right with his car if his calculations are correct.

 

Well you arent the only one who hasnt experienced the issue but then again neither is he. I had about 11-14 mpg avg in my new sixxer. Had 60 miles when i pocked her up. As i got near 3-4k miles i was reading 21avg with some spirited driving tossed into the normal commute. His case is no anomaly

 

well, i filled my car up today with gas.. I will let you guys know how may MPG i get when i fill up again and do my own calculations. I reset the trip when i filled her up.

 

I get 14.5 when I drive hard 16 when I drive normal.

 

You have to go on a somewhat decent cruise and reset the MPG. That will tell you what u are getting. Around the city with mine I get no where near the 17 if im having fun with the car. I've had as low as 11. I can't go a full tank of gas in the "city" driving easy, I always end up getting into it.

And if you leave your MPG gauge at say 12 and go on a long easy cruise, the MPG aren't going to increase much because it's an average. So reset it first. I got 23.4 MPG on a 100 mile cruise.

 

My numbers have been increasing as times goes on.. Under 300 miles average was 13-14mpg after 500 miles I am over 20mpg.. And increasing. So like said has to do with break in period (that's you braking in the car and it learning you)

 

I've gone thru plenty of tanks of gas well under 200 miles. It all depends on driving style.

I do get a ton of black soot on my tails tho that drives me crazy and it comes rather fast.

OP, is the car a DD or weekend/fun car?

 

Not sure I agree with not being able to have fun and get the MPG... our '13 GT auto is getting 20 city and 27+ on the road. Though here in the mid-west...things are flat and far between...so city here does not meant the same as on the East Coast.

 

Yep, that's why everyone's case is completely different and hard to compare

 

I personally have been using this calc (http://www.csgnetwork.com/gasmileage.html) for the last few years, but the metric version and it seems to work quite nicely. Right now I seem be averaging about 19MPG or so with mixed highway (35%)/city (65%), but I don't take it easy for the most part

 

Just stumbled on this thread; I've always felt my 5.0 gets worse gas mileage than most others. Totally stock, my car would get 14-15mpg in mixed, but mostly city, driving. With 3.73s, wider tires, and race tune, I'm getting 11mpg around town. I have 20,000 miles on the odometer now. Guess some are thirstier than others.

 

My mpg has been pretty crappy but then again my car only has 400 miles on it. I have been averaging between 12-14 but I have only been driving city roads during the break-in period to ensure the engine is seeing various rpms rather than cruising on the freeways at a constant rpm. Hopefully that improves once I get it broken in.

 

Now 11mpg seems really low, especially for running a tune, unless you are constantly romping on it.

Try out a different brand tune. Ive noticed very different mpg numbers going from tuner to tuner.

 

23-27 mpg here during regular driving . Steeda 93 tune. Auto tranny