When I bought my truck, the 4.6 STX reg cab, that I test drove, felt considerably quicker than the 5.4 XLT supercab that I purchased. Both have 3.55.

I figured it must be the weight difference, but it did seem quite a bit quicker. The STX had 17" aluminum wheels, while my xlt has 17" steel. That was probably a factor. But I wasn't really expecting the 4.6 to feel that much quicker.

edit: both were 07 model year.

 

im debating over the 4.6l and 5.4l would you mind telling me what yalls mpg was for 5.4 4x4 and 2x4 and 4.6 4x4 and 2x4 thanks

 

It has been almost a year since I bought my 2010 Lariat Screw, I wanted the 4.6 at first because I thought it would be way more economical, only in my mind?
I'm a big guy and with the limited options pkg that are available with the 4.6 it just wasn't a comfortable ride for me, hard to go down from a Lariat with a 6 way heated power leather chair to a split bench.
Even if you look at Fords MPG ratings for the 2 engines the difference is minimal at best.
FS

 

I've probably got more experience with 5.4 and 4.6 liter motors than most folks here - all in virtually identically optioned trucks. I've owned a 1997 4.6, a 1999 5.4, a 2002 4.6, a 2005 5.4 and finally now a 2010 4.6. All were regular cab, short box, XLT, 4x4, automatic transmission with 3.55 LS rear ends. Let me focus on the 2005 and 2010 trucks though.

My 2005 had the 5.4 / 4 speed automatic and the absolute best mileage I ever was able to coax out of it was 16.9 on the road once - and I'm a real feather foot.

My 2010 has the 4.6 with the 6 speed automatic - and I had to go with a 3.73 LS rear end. The absolute best I've ever been able to coax out of this truck is 19.2 MPG - again on the road. So the real world difference is about 2-3 MPG in my personal experience. Oh, and I should add that my current 4.6 would flat out run away and hide from my 2005 5.4. I attribute most of that to the new 6 speed automatic. (Somebody else actually posted 1/4 mile times for two similar trucks in another thread and backed up my claim.)

But as my buddy Quintin so correctly stated early on in this thread, the heavier the truck, the smaller the advantage you're going to see with the 4.6 because it will be pulling so much more weight. Short box / regular cab trucks are pretty much the lightest combination out there.

 

It will all depends if you try comparing a 4x4 3.73 gears to a 5.4 or 5.0 that is a 4x2 and 3.55 or 3.31 the difference will be small. Same package I would think 2-4mpg better all around on the 4.6. personally this is my opinion, if you are getting the truck just to have a truck and dont tow and haul small loads than the small engine is for your. But you plan on doing some towing and what not then i wouldnt bother. Take in mind the initial cost of the smaller engine will be smaller but you will also take a great hit at trade or have a harder time finding a buyer, as there isnt a huge market for these trucks with small engines. I would almost say if you just buying the truck to have it, look some the cars or SUVs these days that have AWD or 4x4 and will actually get better mpg and be better on resale and probably cost less than the truck