04 f350 dually tire size - Diesel Forum

rfishoutofwater · 05-03-2009, 02:04 AM

I have a question. I am looking to upgrade my tires on my 04 dually crew cab 4x4. current factory size is 235 85 16. whats the largest tire i can put on it with out lifting. I am going to be getting some of the big rig wheels and those are 22.5 but that wont be until next summer 2010. I am due for new tires now so I am looking for other options until then. My concern is the duals. anyone running a different size that will fit factory wheels?

**SmokeyWren** · 05-03-2009, 11:42 AM

Your wheels are 16"x6", and Ford installed the biggest tire that will fit on those rims, per the tire manufacturers.

You can go up one smidgen with no problems, other than the tire makers all say you need 6.5" wide or wider rims. That size is LT255/85R16. I've seen the Cooper Discoverer S/T LT255/85R16 on a buddy's dually, they looked great, and he had no tire problems with them on his truck. Not many tire makers make that size, but there is a decent choice:

BFGoodrich MudTerrain
Cooper Discoverer S/T
Toyo Open Country M/T

Those 255/85s are 4.58 percent taller and a bit wider than your stock tires. So your speedo/odo/tripmeter will be 4.58 percent slower than it is now. If your speedo is dead on accurate now, with those 255/85s an indicated 70 MPH will be over 73 MPH per Officer Bob's radar. And an indicated ticket limit of 74 MPH will be a "Howdy, Judge" 77 MPH.

Some folks say your speedo is fast now and the 255/85s will made it close to accurate. Ask your GPS. Or Officer Bob.

Any Ford dealer can calibrate your speedo to make it more accurate. Most will charge about one hour labor rate.

Wider tires than 255/85s can be mounted on your narrow rims, but that can cause all sorts of problems of rubbing between the duals and rubbing on the front end. I wouldn't go bigger than LT255/85R16 on an '04 dually.

daveb198 · 05-03-2009, 12:02 PM

I running BFG AT's 265/75/R16 Load E tires. Love them. Smooth and quiet ride. Plus very durable. Plenty of space between the rear wheels

rfishoutofwater · 05-03-2009, 01:49 PM

thanks for the info. i was thinking of the 265 75 16 but just wasnt sure if they would rub.

**SmokeyWren** · 05-03-2009, 04:41 PM

Quote:

Originally Posted by rfishoutofwater

i was thinking of the 265 75 16 but just wasnt sure if they would rub.

LT265/75R16 requires a minimum of 7" wide rims. Your stock rims are 6" wide. So if you go with that size tire, you should also go for new rims that are 7" to 8" wide.

rfishoutofwater · 05-03-2009, 06:16 PM

i think i will stick with stock til i get the new 22.5's. thanks guys