Odd things are not adding up with numbers...
 

New here still, dont know to much about my car... but somethings not adding up, I have a 2010 v6 premium mustang, advertised with 18city/26hw mpg and 210hp with 240 torque.... but my car is getting milage like a 2011+.... I am getting 35.5mpg highway when I drive her right on cruise control and I am getting about 22-24 city.... no significant mods besides CAI and duel exhaust but the numbers were about the same before.

I still don't see how all the v6's on this forum get better mileage than me.
I get 15-16 city.
Dunno bout highway. never made any big trips.

I swear there's something about the 2008-10's that cause them to get way better mileage..

ha i have no idea, im trying to figure all this out with my engine, and from what I guess your street tune and not driving to save gas might be why? ha

btw sweet decepticon emblem, where did you get it?

Are you resetting your on-board at the gas pump when you fill-up and NOT TOUCHING IT until the next fill-up? If not, you're not getting a true average. Also, the majority of the on-boards tend to be a little inaccurate to the conservative side. If you hand calculate you'll get more accurate but probably a little lower numbers. The onboard on most of the S197's tends to be high by about 1.5-2 MPG. On the other hand, my wife's 06 V6 is near dead on. She hand calculates and it's usually within 2 tenths of a MPG.

You can manipulate the throttle to get all sorts of amazing instant-read numbers. Do some actual manual calculations at the pump and you will not see numbers anywhere near 24 city 35 hwy, lol.

ive NEVER seen a 4.0 get that kind of mileage.
im lucky to get 16 city

i know i can maniputlate the throttle, if i wanted to i could coast down a hill and say i had 70mpg, but i just went on a 60 mile trip and when i got there mpg on the dash was 3.5 average mpg.

I suggest hand calculations, and not just for one fill-up. It's unlikely you will fill the tank to the exact same point each time. Over time, you will be really close on your mpg, unless the odometer is inaccurate for one reason or another.

thanks for the help guys

I drive maybe 5 miles city and 8 highway to work and I average 17mpg cruise control at 65 with 4.10s, if I do nothing but highway around 26 mpg. Its bad though usually 250 miles from E to F.