I just ordered an '09 F-250 Superduty with the option for 20" rims--it will come from the factory with LT275/65/R20 tires. I was thinking of putting on a set of BF Goodrich All-Terrain K/O tires in a LT285/65/R20, but I have a couple of questions:

1) Will the LT285/65/R20 tires, which are 34.7" tall, fit on the truck without rubbing in a hard turn? I ordered the truck with the heavy service suspension package which should give it a little more clearance, but I will be putting a winch on the front which will somewhat counter the height gains.

2) The spare is a LT275/70/R18--will I be able to run that spare with the LT285/65/R20's (approx. 33.2" tall) on the other 3 tires without toasting my gear boxes? If not, will a LT285/65/R18 fit under the truck as a spare?

 

I have Toyo Open Country M/T 35x12.5x20's on my stock 20" wheels and I have no rubbing at all.

 

Yes to all your questions! Remember though ~ a spare is just that, A SPARE!. It will work for a short term and the feel will be different with a different size/type tire., but it will not harm anything!

 

if you want bfgs id go with the 305/65R18. they will also fit with zero rubbing.

 

315-70-17s fit on aftermarket wheels. i think the wheel wells are the same on the 08' and the previous models....