Ok...I hope this is my last question for awhile. Whats the largest tire I can fit on my '05 F350 SD DRW 4x4 CC ? Tallest, widest...etc ? I heard something about making sure they dont rub together on the backs ? The truck now has LT 245/75 R 17 121/118 R Load range E. Thanks again for all your help.

 

Anybody ?

 

Sigh

 

I have no idea, but I didn't want you to feel ignored.
Can you check with a local tire dealer?

 

Thanks BPD...lol.

Somebody must know.

 

I have 33" (285/75R16E) tires on my '03, but it has leaf springs with a helper leaf to bring the spring rating up to 6000# for the snow plow. I think you can go up to about 35" but may have some rubbing issues at full lock when turning, and may need a leveling kit. I prefer taller tires but not wider ones, but the width will matter as far as rubbing. Also, if you are getting new wheels you need to check the offset and backspacing. I believe more negative offset moves the wheel outboard and will allow wider tires. Sites like Tire Rack have articles on all the technical issues.

 

Thanks for the response sir. I'm looking more for tire height than width. I'd like to get the tallest I can without getting into spacers (but I'll use them if I have to). I'm keeping the stock wheels cause they are nice. Was just hoping to get a little more height when I buy new tires.

 

I use Tire Size Calculator - tire & wheel plus sizing

to play with different sizes and see the availability of different sizes

Some folks claim up to a 315mm will fit the F350 with no need to lift or add spacers

Some words of caution:

Ford uses :Hub centric" mounting most cheaper aftermarket rims are "bolt centric".... the later will work but are not safe in my opinion if the truck is worked hard with heavy loads on twisting roads

In my sample below note the required rim width for the larger tire

The rear duallies require specific clearence BETWEEN each tire...Tire rack and other such sites will let you know if they will work on a duall rear wheel fittment

Be sure you look beliow at the revs per mile and understand that the Ford Tech can only adjust the speedo so far (I forget the upper and lower limits) however if you want to fool the computer there isa device called a TrueSpeed modul that you can insert between the VSS in the diff and the PCM to correct for the error

here is an example of the search at 1010.c om

Stock Tire - 245/75R17 new> 315/70R17
Section Width: 9.64 in 245 mm
Section Width: 12.40 in 315 mm

Rim Diameter: 17 in 431.8 mm
Rim Diameter: 17 in 431.8 mm

Rim Width Range: 6.5 - 8 in
Rim Width Range: 8.5 - 10 in

Overall Diameter: 31.46 in 799.08 mm
Overall Diameter: 34.36 in 872.74 mm

Sidewall Height: 7.23 in 183.64 mm
Sidewall Height: 8.68 in 220.47 mm

Radius: 15.73 in 399.54 mm
Radius: 17.18 in 436.37 mm

Circumference: 98.83 in 2510.2 mm
Circumference: 107.9 in 2740.6 mm

Revs per Mile: 661.1
Revs per Mile: 605.3

Actual Speed: 60 mph 100 km/h
Speedometer1: 54.9 mph 91.5 km/h

Speedometer Difference: - Speedometer Difference: 9.218% too slow
Diameter Difference: - Diameter Difference: 8.45%