I have an 05 4wd Stx w/ 4.6 v-8. Its got a 3 inch leveling kit and 305/70/R17 summit mud dawg tires. Cant hardly spin the tires when its raining and only getting 13mpg (on a good day). Advice on profomace gains. Only have a K&N as an upgrade.

 

Sounds like you should change your rear end gearin'(and front since its 4wd).

 

+1 on the upgrade the diffs. That will help alot. When I get the free cash available it will be done on mine.

Sometimes I really get kinda tired of everyone on here ******* the 4.6 but I have absolutely no problem with mine. It seems that the ones who talk smack about the 4.6 being a dog compared to the 5.4, they are also the ones who say that these are TRUCKS and not a Mustang or something and aren't made to go real fast. Fine...that just means that I can get to 75-80 with no issues and a reasonable load in the bed of my pickup...hell just ask my friend...had a bed load full of guns and other fun shootin' stuff, plus the back of my ext cab loaded from the floor to the roof with stuff. Had no issues doing the speed limit +5. In fact, I got about 18 mpg. But oh....wait....don't tell that little weak ole 4.6 that its just a car engine!

I lol at some of you guys...what was the 289 or 302 originally? or the 265 Chevy?


BACK to the original poster....

Get the gears, but I would get a tuner first...Edge or Gryphon probably, then some exhaust...then get your gears...the gryphon will wake up your shift points nicely and give you an extra 5-10 hp I think. Plus it makes for a nice monitor.

Have fun bro,
D

 

Forgot a mod... Power Aide Throttle body spacer (not much power gain, but rice rockets try to race me thinking i have a turbo). There is nothing wrong with the 4.6, it got some oomph to it, i think its just not preforming to its potential.

 

yeah...sorry 'bout that rant on your post.

That spacer....did it at least give you something noticeable? Anything you can feel in the seat of your pants?

 

well its nothing serious, but it does add noticeable power on takoff, but i really think it takes away from higher RPM ranges, but then again - Its not a nascar, its a 4WD. How well do you like your edge programmer, im thinking of going that route. Noticeable differece in power? fuel economy?

 

I am NOT going to say that it gives me 25 mpg or an extra 40 mph on my top end.


I will say that it makes this truck shift like it had a very nice valve body kit installed. AND it also, with the average MPG listed on the display, makes me very aware of how I am driving...I would say that it takes samples of speed, throttle, load and fuel tank levels several times a minute. So its a very dynamic reading, not like the avg MPG on my wife's Escape Ltd. It takes an act of God to get that thing to change any.
But back to the question, my MPG has improved due to that awareness. I get about 18 to almost 19 on good trips of 60 miles or more on the freeway. In the city, I get about 14-15 depending, sometimes more. So I get what the sticker said I would get.

Plus with those large tires, you can recalibrate your speedo with this little guy. OR just use the speedo feature on the edge/gryphon. I would suggest the gryphon as it is an upgraded version and a bit more powerful...I will be sending mine in soon.

D

 

with the smaller engine (not bad mouthing it) and larger tires w/ lift i think saving the money you would spend on the programmer or anything else for that matter and get the gears done.

$300-400 for a entry level programmer and about $800-1300 out the door for gears depending on the shop and that will give you most noticeable boost in power. Then do the programmer unless you can do both around he same time.

 

If he switches out the gears will it make the mpg worse or will it stay around the same?

I considered switching out mine but never did for fear that my mpg would drop a considerable amount.

 

With him already getting 13mpg, it can't get much worse. Gears will most likely improve his MPG because it will take alot less pedal to make it perform like he wants it to. Now, That said, if he goes to high (numerically), and gets something like 5.56's, his mileage will suffer more, (but it sure would be a fun stop light chaser). If he has 3.55's now, 4.10's should work well. if he is already at 3.73's, 4.56 would be the next step up. (I know, actually 4.33's would the next step, but good luck finding those for a front 8.8).

 

even if it IS a 4x4 I am thinking that he has the same as I have...the 3.55's.

I didn't know that they actually list a Yukon ring and pinion in 6.14...I can only imagine what that would do for your highway cruising.


noticed however that for 4.56 and above you need a cross pin shaft that has been notched...is this for clearance I assume?