I range anywhere between 15.5mpg to 17.5mpg depending if I am cruising at 65 or 80mph.

I would do at least the 4.10 or 4.30 due to the weight of the 22's. If you have the 4.6 then the gear change is a must if you have a 5.4 then you are kinda 50/50.

I planned on a gear swap before I went SC because I do tow a 7k lb boat, and I wanted a little more pep in traffic. Bar none a gear swap is a great bang for the buck.

 

thanks for all the great info. ill probably just wait on the gear change then.

 

How much more do 22s weigh than say the stock 17s?

The towing package gets 3.73s instead of 3.55s to increase the towing load 3000+ pounds. Why would a 60lbs (just guessing) difference, minus however much less the lower profile tires weigh, say 40lbs total now, require a gear change at all?

 

My truck has the towing package and it was geared to 3.55. Unsprung weight and rotational mass increased when I went to the 22" wheel combo.
I gained 26lbs on tire weight only and another 33lbs on the wheel for a total of 59lbs per corner. You now have an additional 118lbs of mass to accelerate and stop, so changing gear size will help.

If I had a 4.6l then a gear change would be high on the list of priorities. I have a 5.4L and I did drive around like that with the stock 3.55 gear and it was ok, once I changed it was like a new truck. Also going from a stock tire height of 30" to the new tire height of 31.5" a gear change will help with the larger diameter tire.

 

Really? I could have sworn the towing package was the auxiliary cooler, a bigger battery and alternator, 4 and 7 pin hookups, and a 9.75 axle with 3.73 gears.

Unsprung weight increases surely affect the handling but 118lbs isn't even what they consider an average person. Basically, now your truck is considered full with three people not four. I don't see how this by itself necessitates a gear change whether you have 215HP, 265HP, or 305HP.

This isn't the "Also". This is the actual reason the gear change needs to happen. The circumference of the wheel changes the overall gearing of the truck. Changing the gear ratio can bring it back to what you're used to.

I do completely agree that changing the gear ratio will affect the performance of the truck. But it also decreases the gas mileage so its not a change without effects. Its no coincidence that the 21MPG claimed on the 09 F150 is on a truck with 3.05 gearing.

 

my truck also has the towing package. 3.55 gears here.

 

I wonder what option was selected on my truck to get the 9.75 axle with 3.73 gears then. Hmmm.

Either way, the 3.73 gears add like 3000 lbs to the tow rating. So I don't see why, by itself, adding even 200lbs of weight to the wheels requires a gear change. Upgraded brakes, maybe. Gears, no way.

Its like saying you need to change gears if you have a passenger with you.

 

Well in my case I have a crew cab with an extra 236lbs in wheel weight plus a wife and 4 kids which pushes my truck over 6k. Having the steeper gears puts a lot less strain on the engine to get the amount of weight moving.

I am not saying you have to change gears when going to a 22" rim I am just recomending the gear change because the trucks are sluggish with the 3.55 gears even with the 5.4L. My wifes truck has the tow package and 3.73 gears with the 5.4L and she is rolling on 20's, it has enough pep for her but I would like to change gears but going from 3.73 to 4.30 doesnt justify the cost for me at this time and I dont want to go to 4.56 in her truck. On the other hand if she was equiped with 3.55's then I would change them. Heck I might just put my rear end under her truck then regear hers to 4.56 for my truck.

 

I went from the stock 18's to stock 20's and 3.55's to 4.10's. I don't know that it was necessary but it definitely helped out acceleration big time. I lost probably a mile per gallon or so highway cruising tops.

 

My truck is an '05 XLT 5.4 tow pkg. (aux trans cooler) with 3.55 gears 17" rims

my roommate had a 07 Lariat 5.4 tow pkg... with 3.73 and the 18" rims, the stock tires were a size larger on his and thats where the gear change comes in I believe

 

3.73 gears help with bigger tires but the reason Ford offers 3.73 is to maximize the truck's tow rating and GVWR. My numbers are a bit off, I must have been thinking 4.6l engine too but basically 3.73 gears and 17" wheels gives you 1000lbs more towing capacity. 1500lbs more in comparison to 18"+ wheels and 3.55 gears.

https://www.fleet.ford.com/showroom/rv_trailer_towing/2006/06RVttslctrp16Jan06.pdf

 

good information to have

 

I'd say 4.56 is a bit steep. Especially if you care about your gas mileage at all. Maybe with the 4.6L. or on a 4x4 with 50" donuts.

If you go with 4.10, 4.30 from 3.55 you'll definitely notice the difference. Of course the speedo will be way off too.