I got my new mustang yesterday and took a road trip about a 100 miles after the 30 mile drive home. In heavy heavy traffic it was getting 14.5 or so on the way home. Left for my destination and the MPG kept rising even after I was shifting a lot of keeping the rpms moving and giving it some good throttle once in a while (50-60%). It crept up all the way to 18. The next 60-70 miles were a lot of accelerating and cruising at 50-65 mph on back roads and i averaged around 17.5. Coming home at 55-80 I was in 4th or 5th gear and sometimes 3rd accelerating and decellerating with traffic and on my own for the break in. I reset my computer when I left and after a 100 miles I was amazed to see 25.6 mpg. This wasn't perfectly flat ground either. If I had just set the cruise control at 70 or 75 would i have gotten 28mpg? I just see it really hard for me to be getting that good of mileage with 250-350 miles on the engine. I'm super happy because this is an added bonus. It offsets the bonus of me getting the wrong wheels with the car. I don't mind the 18" bullets but i wanted fanblades. Anybody want to trade thats in WA state contact me. The car itself, as everyone else knows is amazing. Theres a couple of minor things like the carpet not being tucked in all the way and a minor scratch but other than that it's a great car. The exhaust sounds *Almost* good enough to leave alone.

 

You just got the car, the computer is just figuring things out. You are not getting the MPG you think you are. Of you want to truly track it, you have to keep a record of milage travelled verses fuel consumed. Give your car a couple thousand miles, then the message center will be a bit more accurate...

 

I'm very surprised so many believe the computer to be accurate. I've found it to be off by 2-3mpg either way on any given tank.

Maybe 25.6 was your average mph, not mpg. It shows your that as well, not sure why.

 

That's a good point. Also when you're old like me little letters of MPG/MPH look very similiar.

 

you also have to remember the computer is doing an average, if you keep hitting the reset on the MPG then it starts averaging over. The less miles you have on a new tank of gas and reset the more it is gonna rise and fall. The more miles you have on the car the longer it takes to increase or decrease the MPG. I usually do not reset the MPG until after 3 tanks of gas, just so i can get a better idea of the true MPG i am getting.

I did a test last night, got on I95 and reset the MPG, By the end of my 35 mile ride i was averaging 25.6MPG, but this was pure highway driving, now once i start doing town driving again, depending on how much highway/city driving i do, i will probaly average around 18 or 19 MPG. But to be fair, most of my driveing is city driving and that is why mine is usually so low.

 

This was after a 100-110 miles. It was all freeway driving and i worked about how many gallons i'd burned and how many miles i'd gone and it was pretty close. As soon I start driving around town it goes down to around 22 and is wavering from 21.5-22.5, lots of cruising at 35-45. I also understand how the computer works. If your off by 2-3 mpg per tank then it was probably that you did a different kind of driving than your "average" has been since you last reset it? At least thats how it was on my SD.

 

Yeah, the computer seems to do a great job overall on miles per gallon displaying. Pretty neat driving as you go feature on a car. But why can't a new Mustang have a thermometer and compass in the rear view mirror?

 

My computer seems to be very accurate. I avergage 26 MPG on the highway and Lord knows what in the City. I don't even try to track city driving. Running the gears are the best part of having a 5 speed so I let her rip! Probably 14 to 15 MPG City.

 

LOL i noticed if i really rip around town it does drop reallyyyy fast.

 

Amen to that.