Howdy guys, Its a done deal I got the new f-350 It has 285 BFG ATs on It and a I remember someone talking about the change in gear ratio that would make. Does any one remember? I am concerned that when I hook up to the camper I will notice a differance it towing.. If any one has practical experiance in this please let me know

Thanks and as always
Take Care
JT

 

its the diameter of the tire that counts not the width. p285 is your width. i think you should be fine. does it have l/s or the tow command system.

 

Im not shure what you meen by I/S? It is a 2003 so it does not have the tow command like the new 2005. The tire size is 285/75R16.

 

Found this to be a pretty good calculator. Try it.

Just ignore the source.

http://www.dakota-truck.net/TIRECALC/tirecalc.html

opps, just saw they don't have the 373

 

That is a sweet calculator! I wish it had 3.73s so I could check it out for shure. I know it was posted here before, Ill have to do a search and see what I can come up with.

JT

 

Ok I guess I could have done this from the get go but I like to do things the hard way! From the info I found on a search I have taken my Gear ratio from 3:73s to 3:60s... Does this sound correct to anyone? And what will that do to the performance when pulling the TT and boat? How about milage?

Thanks for the input
JT

 

I didn't notice any diff in power or milage when i went from 265-75-16 to 285-75-16. I could still tow my 18-7 cargo trailer 85mph with no problems. After 6"lift and 35-12.5 I have to tow my trailer in 3rd gear.

 

Hey I'm in the exact same boat as you, I will at sometime switch the gears but mine does pretty good with the camper and boat (check gallery). I have an 03 CC SB 4x4 sport with 285/75/R16s and the 3.73LS rear end. My Truck/ Camper/ Boat and gear for a long weekend scaled a weight over 16k so with me the wife and the dog and other garbage thats loaded onto the truck we end up closer to 17k combine weight. the truck does pretty well. I don't tow in OD as I would only be turnin 16-1800 rpm at towing speed so I usually run in 3rd at about 23-2500 rpm which puts me around 60-65mph giver or take. it tows great as long as you don't use OD or Cruise and play the hills a little (gain a little extra going down and lose a couple goin up) for the most part I have no problem maintaining 60-65 through moderate hills and headwinds. on the two steepest grades between my house and the lake I use 2nd which produce 4-4200rpm at about 65mph, heck I have enough left over to accelerate up the hills when in 2nd. In 3rd on the same hills I would lose probable 5-8mph or so which isn't the end of the world either if you don't want to listen to that v10 singin over 4k (I personally love the sound and feel, heck I look forward to those two hills). I think with the addition of 4.30 gears it should never see 2nd gear and would be able to use 3rd on the steepest of them.

You've got the exact same setup as me so unless your towing over 10k or running through the mountains you should be fine. don't swet the small stuff that V10 has some grunt and even with the 3.73s and larger tires it's still no dog, just not quite as good as having 4.10 or 4.30s.

 

Yup.... or thereabouts.

I think it's closer to 3.47, but I'm tired and can't vouch for my accuracy

3.60 sounds right though...

You may or may not notice the difference.

 

If you had 265/75/16's to start and you went to 285/75/16, you will not even notice it. You're talking about less than 1/2" increase in tire diameter, no big deal.

 

check the tire calculator site again on the right hand side, you can put what ever numbers you want in.