My 2006 5.4 4x4 cruises at about 1600 rpms at 50mph, according to my tach, which is causing the transmission to downshift at any slight inclines. I'm sure this isn't good for the transmission. I know its because I have 33" tires and stock 3:55 gears. I do plan on re-gearing to 4:56 but the money is not quite there yet. The truck is completely stock. Will a tuner do anything to help in this situation or would it be a waste of money?

 

It would help a lot... you can set torque converter lock-up and shift points, at least with an edge you can.

 

What about Bully Dog? My old truck had one when I bought it but I had no idea how to use it.

 

If that is the case, what is the point of re-gearing? Seems like a cheaper route going with a tuner. I'm not sure I understand how it all works but I'm sure its not that easy.

 

is you mpg crappy right now?

 

not familiar with bully dog.. I have an Edge Evolution. I don’t see the need to re-gear with 33’s ... 35’s maybe .. 37’s for sure. I don’t have your gears either so, not sure how it feels with 3:55’s

 

I ran a PHP Gryphon tuner in my 04 and it made a world of difference in MPG, shifting, and RPM's. I would go with a tuner before re-gearing. I also had the 5.4 and 3.55's with 33's. Tuners can unlock and almost infinitely adjust your shift points and air to fuel mixture to fix the downshifting.

 

I don't check it that often but I don't think its that bad probably 15 or 16 mpg. Not too concerned about the mpg if its only gonna change by a couple.

 

Wish I got 15 or 16 MPG... that would be awesome...

 

i get about that in my 4.6 on the highway not pulling anything