Fox Body Mustang 5.0

[UltArc]

Originally Posted by mrsilent13

well in that case after reading that....i guess ill stick to 2.73 for now

If you want better highway, you'll want to deop it even firther. i have the 2.7s and replaced my 17s with 18s. Pick up tire size, and highway cruising becomes more fuel efficient(for the most part).

[mrsilent13]

yes i got rid of the engine driven clutch fan that was stuck anyway...so i installed a complete stand alone unit with built in thermostat...between 180-220....would it be a good idea to turn the thermostat up to have the heat do more of the burning..i currently have it set to 180...i guess ill try that experiment out once i get the MPGuino to see if theres an actual difference...but on the highway it wont make a difference

[mrsilent13]

yes im thinking of doing an air dam/grill block...havent really looked well into it...but i am thinking about it

[mcrews]

Originally Posted by UltArc

If you want better highway, you'll want to deop it even firther. i have the 2.7s and replaced my 17s with 18s. Pick up tire size, and highway cruising becomes more fuel efficient(for the most part).

He's right.
Even going up a size on the 15s will help.

See my threads in my signature.....
245/45/18 is stock
am running 245/50/18 on stock rim
went from 26" to 27.5" in diameter.
keeps my rpm low at highway speeds.

It will slow down your 'launches' but hey.......

[mcrews]

dont need a vacuum gauge if your running the MOGuino

[mrsilent13]

well i am running 225 55 16 i guess going a size up on the rears and leaving the front stock would not affect it too much...or do i need to swap all 4 tires for the taller size?

[UltArc]

You want to swap the drive axle, so rears for you. And there is a terminal point where bigfer tires will be more harm than help, but i don't think a reasonable person will encounter that. If you do 16s front, 17/18 in back, you will help lower engine rpm, and create a low pressure zone under rhe rear of the care- more downforce, in theory, but that, in theory, means more drag.

Edit:
From my limited time on the site, mcrews knows his stuff. His guides are pretty good, and you might want to go his and my route and buy a more aero efficient front fascia. Just an idea.

[mrsilent13]

yes im looking at getting a GT front or at least something to create the air dam

[GRU]

keep the stock gears because if you go to 3.55 you will get worse mileage on the highway....look into some aero mods, i'm sure for the mustang there are some front air dams that look good and divert the air from going under the car...or do a belly pan

[mrsilent13]

yes im actually looking at mcrews belly pan right now...that thing is amazing