dblack1

with 4.10 gears what kind of highway gas mileage will I seeing on a auto mustang gt
what would the rpms be at around 60 mph

woulduno

With stock tires and axle you are turning between 1900-2000 rpm at 65 in 5th, with a 4.10 you will be turning about 2200-2300 rpm in 5th. I used this calculator to get the calculations and this site for the trans ratio's. If you have different tires, it may change it a bit.

As far as MPG, I can not speak to that.. Mine is not a daily driver, and thus when it is out, it is out to play..

But, for the most part a 4.10 swap out is the most effective mod you can do to this car. The exhaust is pretty well tuned from Ford, maybe change out mufflers for sound, and throw in a CAI. Beyond that you really don't get much bang for the buck until you slap an S/C on the car..

Scott

Mpaint99

Turn off your overdrive. Thats pretty close to how it feels at higher speeds.

casperorr

I have a 2007 Mustang GT. I have owned it now for approximately 1 year. I started out with a CAI and tune from Brenspeed. Got more spunk for the little bucks spent. But wanted more, so I changed out my 3:31's for Ford Racing 4:10's. Big improvement, money well spent, approximately 2600 rpm at 65 mph. Did OK on gas milage running stock tires, (235/55/17's), right around 19 mpg. But wanted more, so I went with new tires and wheels, ( 285/40/18's on GT 500 wheels, 255/45/18's on GT 500 wheels ), and gained back one mile per
gallon = approx. 20 mpg). But wanted more, so I went and installed a Saleen 475 hp Super Charger. This is now the car I always wanted. I am running approximately 2600 rpm againat 65 mph, and I have only checked my milage a couple of times, getting approximately 18 to 18.5 mpg.
Even with the SC and an automatic, this car is now a beast compared to when I drove it off the dealers lot.
Hope this helps,

Casper

jbs07stang

Makes me jealous. I also want a SC.

TheDarkPath

Last weekend, I made a 300 mile trip which was mostly highway driving. I was facing a head wind for most of the time. I kept the speeds between 65 and 70. I got 21 mpg.

Mods in the sig.

Bluestar

Two points worth mentioning, 1) I don't know what Hwy you guys Drive on, where people drive 65 mph, if I tried that on Rt 78, I'd get rearended for sure. 2) One poster claims 2200 @ 65mph, another claims 2600 @ 65 mph.....The fact is you will be very close to 3000 rpm's, when driving on most interstates.....How loud is your Exhaust?, how far will you be driving at that RPM??....just some thoughts on the subject.

casperorr

My correction on the above post. I had to run to the valley today, so I checked my figures again. At 70 mph I am running at approximately 2900 RPM, and I got 19.8 miles to the gallon. That was on the way down and approximately 19.0 on the way home back up. I can live with this for what I have gained in HORSEPOWER!

Casper

Black05StangGT

Horsepower gain?

casperorr

Did you read the thread or just my post. I can only guess what you are asking me, since you only wrote " horsepower gain?"
In the thread above, the beginning post asked about gas milage and RPM's on highway driving. I tried to answer best I could, but I also threw in horsepower gained after my SC installation. I hope this helps, if you need further information about my setup, please feel free to either post your questions/comments here or PM me. This is a great place for help and information while working/upgrading your Mustangs.

Thanks,
Casper