Here's and in-depth paragraph from their site:

Your automatic valve bodied transmission will automatically move all its shift points up by exactly the correct 28.6% speed whenever the overdrive is on. This is because the governor on the trans is in front of the ovedrive so when you shift in the overdrive it slows it down. (On the electronic transmissions we send buffered ratio info to the pcm as part of our kit but its all mechanically done on your three speed - no wonder we all like-em). What is cool about this is that you will automatically get a useable passing gear (2nd -over) at a 28% faster road speed than you currently get 2nd without overdrive. As 2nd-direct is normally too low to do anything but wind out the motor (no headroom) you should find 2nd -over very nice. When it shifts down to 2nd - over automatically and you are accelerating and then the trans shifts back to 3rd without you moving the shift lever (if you want to keep accelerating) hit the Gear Vendors button when you hear 3rd apply and you will be in 3rd- direct. When you are back to just cruising, hit the Gear Vendors button for overdrive.

 

I haven't read through all the posts and I'm not going to either but why in the world don't you just get a custom tuned Xcal2 with a gas mileage tune?

 

It's too easy?

 

Stock 4:10's-no tune is going to take the motor to 2000 rpm at 75 mph.

Here's a way to commute and tow, getting good mph either way.

 

If I do nothing, I will spend $42000.00, at current prices, on gas, over the next 6 years.

 

Why are you driving 75 mph? Keeping the rpm's below 2000 is where you save gas money. Drive 60.

I bought my truck knowing I was going to get 19 MPG, and gas was $2.00 a gallon back then. I drive 50 miles a day up to 7 days a week.

 

60? Were you a stunt driver on CHiPs? Not an option in the SW. Dunes in the west, Mountains to the north and east, and nothing in between.

75 is the new 60.

 

OK.

 

Why don't you just regear to 3.55 or 3.73's. With my 3.73's at 70 mph I am running around 1900 rpms with the stock tires. You can get the truck regeared for about $1200-1400 and just back under the magic 2000rpm where the mileage goes to ____ at.


IMO, you trying to spend lot of money in hopes of saving some money. Even if the gear vendors unit does increase your mileage by 4-5mpg, how many miles it is going to take to get the $3000 for the unit (not including shipping or install) back out of it.

 

How true that is. I was once given a ticket in SoCal for doing 55 in a 55. The officer ticketed me for impeding the flow of traffic, then told me that he would rather have me doing 70-75 and giong with the flow.

SuperSlab

Have you considered swapping in a complete rear out of a wrecked F-150 with a 5.4? The standard duty 150's have a 9.75 rear which is lighter than your 10.25 and has 6 lug axles, and should be a direct bolt-in. Then you have a lot more wheel and tire choices, OEM and aftermarket.
For the front just swap in standard duty front hubs that are 6 lug w/ 6 lug rotors. You might be able to scrounge the hubs, rotors and even the front axle assy from the same truck you get the rear out of if they are not damaged.
Unless you continually load your truck up to its GVWR, the 9.75 rear can handle your truck no problem.
Ohh, did I mention that gears are cheaper for a 9.75 than for a 10.25.

 

If it were me, I would ditch the AS and do a 4/7 drop (2" lowering coils and 2wd shocks for the front)(3" drop leafs, 2" shackles and remove the factory 2" blocks for the rear).
Then do a 6-lug conversion and put on some Harley Davidson 22's with some 305/40's then you truck would look awesome, Long and Low

 

I'm not sure that its alot of money considering the upside.

1. A Gear Vendors unit would give me the best of all worlds. I do occasionally tow a Bobcat & Trailer that weighs more than my truck, and it would be cool not to rev it to the moon to get it off the line.

2. Keeping the motor in its peak power range would put less wear on it.

3. I commute 80 miles per day, and when gas prices fluctuate, like they're about to again, my gas budget gets screwed up.

4. I consider post-tax income spent on gas a complete waste. Might as well spend some money now, to save a lot later.

5. Conservatively, I get 10 miles per gallon. If gas is $3 per gallon. That's
$.30 per mile. If I were to get 4mpg more, that would be $1.20. So the GV would be worth $1.20 every gallon. $3000(GV price)/$1.20(Money saved) =2500 gallons. My tank is 35 gallons. 2500/35=71.43 fill ups.

52 fill ups a year. It would take 1-1/2 year to pay for itself.

6. I don't plan to sell this truck ever. It will be my designated tow vehicle, and I should be moving into something mid-engined before I die.

 

Guys give it up.....

 

This is a great idea! And is just yopu looking for when you buy your truck but Ford dosn't offer.

 

I have true dual exhaust with MagnaFlow mufflers, Airforce One intake and Troyer performance tuning on a 2006 KR 4x2 with the 5.4 Liter engine. I have lowered my rear with a 2" GroundForce Shackle Kit and I have a Snuglid F2 solid fiberglass cover. Most of this was done to with the "idea" of getting better gas mileage on long trips, but also for performance reasons around town.

With all of those changes, the best I have seen is 17-18 MPGs for long stretches on the highway if I stay at 70-72 MPH. I have tried the 87 performance tune and the 87 towing tune, with the same results. These items cost almost $3K, so I doubt the 2MPG gain will ever pay for itself.

The best thing you can do is slow down, as I have seen my mileage go as high as 19 MPH when traveling 60 MPH for long distances. Of course, this drives me crazy, so I always speed up again to 70-75.

KR- Texas