Problem with Daughters truck maybe

[MegaMouseGW]

Ok I finally got the build sheet for my old truck (it is now my daughters), and found out it has a 3.21 rear end. Ok that might be my fault because I used the truck for a lot of towing. What would yall recommend I swap it too in order to give her better gas mileage seeing as she will not be towing anything after her little altercation with a utility trailer (backing up is not her forte). Her truck ahs the gertrag 6 speed manual tranny in it if that would make a difference in regearing it for her.

OOPS forgot some important info: her truck ahs the 4.7l magnum which I have turned into a HO version, 2wd, crew cab 2007. Other than her taking out the bumper the other day the truck is still rather clean. She wants to have it painted either cherry red or a metallic red. But that will be her next birthday present.

GOD MY SPELLING TONIGHT IS BAD.

 

[NYCruiser]

I would think that the 3.21's would be the most economical and allow the lowest RPM's when cruising. The lower gears are better for performance/towing, but not usually associated with better MPG.

 

[MegaMouseGW]

It does cruise at 1800 rpm's at 70 mph so you may be right. Just seems a bit sluggish off the line.

 

[NYCruiser]

Lower gears will get her off the line better, for sure, but I think it will cost more in fuel.

 

[Statcher1]

3.55s would be a good compromise of performance and MPGs

 

[NYCruiser]

I have 3.55's in my truck and I like them. Not sure its a big enough difference to be worth regearing though. Unless she starts having trouble with the rear, then its a no-brainer.

 

[Bully's Performance]

3.55s would be a good compromise of performance and MPGs

Exactly this ^^^^

 

[ST-8]

Personally I would never do a gear change when the #1 priority is gas mileage.

 

[MegaMouseGW]

Ok thanks guys. Was not sure if I should regear or not. Guess she will just have to live with what she has until they go out. Not gonna tear into something that is not broken.