I see quite a few people sticking 12.5" wide tires on the stock 8" wheels and question if any significant issues exist putting a wider tire than recommended on a narrow wheel? I found a set of wheels and tires that I wanted at discount tire but the first set (toyo RT 35x12.5) did not have a high enough load index for them to sell them for the application. Then I thought I found the Nitto ridge grapplers (same size) that worked but they were 125 LI when a 126 is required. So after the back and forth they were willing to sell the 35x13.5x20 ridge grappler tire to me for the 20x9 wheel without issues. The problem is that I now see the tire minimum reccommended wheel is 9.5" which brings up the question of what issues this may cause if any??? I'm fine with the wider width but I don't want worse handling or ridge quality if it pertains.

 

The 20 inch wheels are actually 8.5 inches and fit within the requirements for the 12.5 tires. The 37/12.50/20 tires I have on have a 3,750 load rating. I can only guess that if wider tires are installed than the wheel is designed for that they will wear faster in the middle at max pressure.

 

That makes good sense. I likely wouldn't run max pressures on a regular basis and would try with any tire to find a good balance of ride quality and good handling but I would like to hear people's experiences.

 

Guys I know, including myself, have been running 35x12.50's on stock 20's or 18's since the 2005 truck came out. No issues at all, I'm currently running them on 2007 wheels. It is said that pre-mature wear could occur, but no one I know ever noticed or worried about it.

 

Epic....I could be wrong...but aren't all the Ford 20's 20 x 8...not 8.5??

 

I just looked at a set of 20" takeoffs on Ebay, you could clearly read the inside of the wheel: 20x8. So from what I can see, Ford has not changed the width on the new truck.

 

The stock wheels are 20x8 according to the literature published on the subject...Epic, did you measure them when building up your new setup? Wouldn't surprise me if the docs are wrong.

OP, I faced the same issue...and early next week have the following going on:

- Toyo AT2 Xtreme - 325/60r20 (35.5"x13")

- Fuel Boost 20x9 +1 offset

These run at 65psi, so I'll drop that in Forescan, unless the tire shop will do it for me. Feels like a great compromise in size, aggressive good looks, and load capacity. PLUS, 50k warranty. Maybe it's 45k...it's not less than 45k. LOL

Also, for those curious, the load rating on the 20" Platinum wheels is 3590, they're made by Alcoa, and have a PVD finish (chrome powder coat).

 

I will have to find the source but I'm sure I read that they are 8.5. I checked that off in my brain right after ordering.

 

Yeah...I really wish they were 20x9. Would make a lot of the tires look better on the sidewall....

 

Epic- The door jamb sticker also shows the oem 20s as 8" wide. Been this way since the 20s were released for these trucks.

OP - go with 295/65/20s. This is a 35.5 x 11.50 tire that is rated for the width of the oem 20s, and it has a Load Index of 129 (4,080 lbs each @ 80 psi). I have the Ridge Grapplers in this size on oem 20s.

 

Ten Characters....

 

My sticker says the same 8.0. I just went through all my paperwork and bookmarks trying to find where I got the 8.5 from but no go. Ugh, all this time I was thinking otherwise. Sorry for the bad info.

 

Those 295/65/20's are such a nice size, they don't rub stock, fill the wheel well nicely, and they get that high load rating.

 

Epic you're not alone, I have wondered this for a while as i have seen conflicting reports. But I can tell you exactly where in the Ford documentation it says 20X8.5".....

ETIS report! My Plat Diesel shows 20X8.5"

Does anyone know the actual load rating for these wheels? I cannot find it in the TBBAS Specifications.

 

I think we have seen that there have been lots of incorrect specs listed by Ford for the 2017s. It would not surprise me if it took a while to work the inaccuracies out of all of its different systems.

2017 wheel specs are here (PDF page 61). The rating for 20" wheels is 3,590 lbs. This is +\- 100 lbs from previous Super Duty 20" wheel ratings so I am inclined to believe it (or at least consider it to be close enough).
https://www.fleet.ford.com/truckbbas...ps_-_Specs.pdf