just wonderin'... because my dad's got a 5.4 f 150 and he had the 3.73 gears put in the rear end and he gets about 20-21 miles a gallon which is almost unheard of for a v8 like that. he'll also get 17 or 18 towing something. so all this talk about gear swaps just brought to mind the 4 10's and 8.8 rear ends and all these other combo's. what would be the advantages and disadvantages. just another curious.

 

advantage would be quicker acceleration
disadvantage would be a loss of 1-3mpg depending on how you drive, do to running at a higher rpm when crusing, then before.

 

If I put the 4.10 in, what would be the (recommended for mpg) shift points?

 

As long as you don't keep your foot in it all day your mileage won't be that bad.You drive a Mustang not a Civic lol

 

just to throw this out there, some have said they get better gas milage in the city but worse on the HW, because they can get into overdrive faster on the street

 

Makes sense.