I just saw a 2010 GT at the dealer while I was having some work done on my '04 F150 4x4 - What a sweet ride! The mileage on my truck has been killing me - 15 mpg max at what is now $2.50 a gallon (I basically parked it when gas hit $4.75 around here) - so I've been considering trading it in.

The GT is EPA'd at 16/24 for the stick. I'm assuming that is with the mildest rear end. I also see that a 3.55 and a 3.73 are options. Does anybody know what kind of an impact the different rear ends have on real world gas mileage?

 

I wouldn't think it would make a huge difference. Your lead foot would be more of a deciding factor.

 

+1

It also depends if you do more city driving than highway.

 

I was wondering about that too. I would think it would affect the city mileage and not on the highway correct? It would probably be minor and have more to do with how much you put your foot into it.

 

if you are doing higher rpms on the freeway with a 3.73 rear (compared to the stock 3.31), how can you expect it to not effect mileage?

 

I would stick with the 3.31 if you want mpgs. IMO the biggest difference in MPG's is the driver. My wife has a 08 4Runner that gets bt 17 and 18 MPG's (mixed city and highway), when she drives it. When I drive it the MPG's usually drop bt 15-16.

 

trade your truck for the stang

 

+1^^^ that is what I was thinking

 

I thought the gear ratio's 3.31, 3.55, 3.73, ect. had to do with 1st gear only? Or am I mistaken and does it have to do with the final ratio, which does'nt make sense to me because that would affect top speed and not affect acceleration much?

 

It is the final drive ratio....which affects both top end and acceleration. Although, in real world terms the affects on your top speed won't matter to you. But if you race at the strip alot it can affect how fast you'll go in each gear before needing to shift.

As to the OP, if you're looking for max mileage...the 3.31's will be the way to go. If you want slightly better takeoff grunt.....3.55's or 3.73's will get it for you. And if you're careful with your right foot, you'll see better than 24mpg on the highway, easily. I used to manage 28 on the highway with my 3.55's when I was still stock.