Will these tires be ok?
 

I currently have 255/65/17 stock tires on my 4.6 scab with 3.55 gears. I am wanting to upgrade to some maxxis buckshot mudders 265/70/17. There shouldn't be that much of a power loss should there? I am only going up one size. Do you think gas mileage will drop? Also is anyone running these tires?

I dont think you'll notice too much of a difference... I went from 235's to 305's and DID notice a difference....but im also pushing around 22 inches of chrome...

I say go for it.... why not go a little bigger as well! :)

You won't notice any difference, tire is only about a 1/2 inch bigger probably won't even look much different. I would go with a 285 atleast myself. No power loss maybe 1 mph difference on speedometer with the size you are talking about.

I went from 245's on my 3.0L Ranger with 4.10 gears to 285's with only a slight power loss. I bet you won't notice a thing.

Better recheck your math. The difference in those two tires is over 1 1/2". Will throw your speedo off about 3 mph at 55 mph. Changes your gear ratio to about 3.37.
You guys can't just look at the section width number (285,265, etc.). You have to also look at the aspect ratio number (65, 70, etc.). Both of these numbers affect the height of the tire along with the rim diameter.

What size tires do you have in the pic?

btw guys, the first number in the tire size tells the width of the tire, the second number tells the height, it is actually the aspect ratio, the percentage of the width that makes up the sidewall of the tire. so saying that a tire is a 245 only tells the width of the tire, to know the height you have got to look at the width, aspect ratio, and wheel diameter. its all tricky to figure out but the calculators all over the internet make it easy.

Mine are 295/70R17 Nitto's they measure at 33.12 tall speedometer was off 4 mph. I noticed no difference in power and actually picked up 1.5 mph per gallon. The difference in what you are talking about is about 1 1/2 inches so that is 3/4 inch all the way around the tire thats not much if you are going for a more beefy look.

What is the biggest size you would go with being I have a 4x4 4.6 with 3.55s? At first I was considering stock FX4 rims and tires but I heard from people this would make me miserable driving my truck. I am not planning on doing a gear swap.

Simply because I would like to better understand.

Does the 1.5 mpg increase taken into account the odometer being wrong after the tire change?

The tire size would alter the odometer as well as the speedometer correct? After all they are measured based on RPMs correct?

Boy I wish I knew how. I've got the same tires and, if anything, get a little worse mileage.

the ford dealership recalibrated the speedometer and said odometer was right to, now. I check going by mile markers and it appears dead on. I guess the increase mileage is because the truck goes farther now with the same engine revolution than it did on the 255's??? not sure but it's better!

the gear change in effect makes you rev lower at highway speeds.