I just bought an '07 F350 KR cc srw 6.0 and it has 18" wheels on it. I like the way the 20" wheels look and was thinking of getting some stock KR 20" wheels or just putting a slightly bigger tire on the 18" wheels.

What would you advise? Is there a performance difference between the 2 that would make one better than the other?
I do about 50/50 city/hwy driving and it will have a heavy plow on it during the winter time.

Also what tires would you recommend for either size?

I'm a nebie, so I appreciate all the advice I can get.

 

If Im plowing I want more sidewall, less rim...
Personally I would keep the 18" rims and wrap them in Cooper ST's or BFG AT's
Those are going to give you good on and off road traction ... and still be worth their weight in the snow. The Cooper tires can be studded, the BFG's cannot... unless they've changed something.

I think you can go up to a LT 315/75 R18E without a lift... that would be close to a 35" Tire.

 

I changed my 18's for a set of 2007 Harley 20's. They look and ride Great!

 

Stick with the 18s. The OEM 20s look the nicest but overall 18s are the best compromise for looks and performance on the F250/350 trucks imo.

 

Being an engineer, I have a hard time putting form before function.

From every functional perspective I can think of, the 18's are superior to 20's.

 

Your stock 18" wheels are 7.5" wide,,,,which will accept 275/70/18/s,,,much bigger of a tire will want/need a wider rim to accept a wider tire,,,,thats the issue I have run into with these 18" wheels,,,I myself like the way the stock wheels look, and find many of those aftermarket wheels, Gaudy,,and look ,like s!%& to me !!

Hopefully more 18" tire options will come about,,,,but man they are some pricey all ready!!

I have been looking for 18" tires ,,,recently my son found on Craigslist,, a set of stock 18" wheels(Bullet Hole wheels) with Brand New 275/70/18 Mastercraft Courser tires on them,,,wheels/tires/4 caps,and lug nuts,,,$750,,,,needles to say,,I now have 3 sets of wheels for my 06' F-350 !!

 

Mine came with the Lariat polished aluminum 20's, and I have no problems towing! I cant tell you about plowing, cause I would never put a plow on my truck!!

 

I agree, many of the aftermarket wheels for ford trucks look like s^&t, but I do really like o/e ford wheels. I have noticed that there are many more selections for the 18" wheels as opposed to the 20".
Based on this and the fact that function of an 18" is better than the 20" I am going to save the money on the new wheels and put it towards a good set of tires, now to see what size tires I can fit on these rims!

 

Toyo Open Country MT's are available in a 285/75/18. That's a full 35" tire that will fit your stock 18's and because they're relatively narrow shouldn't rub. Plus, they're an awesome looking tire!

 

I'm still on the 16" wheels my 99 Lariat came with, partly due to tire prices! IF I go up, it will be to 18's. 20" tires tend to be $50+ more per tire, and I just don't see spending an extra $200 - $400 for that. If they got me an extra 1-2mpg, then sure, but they won't.

As for tires, I have Hankook DynaPro ATm's and they are PHENOMENAL. E rated so no problems towing. 24"+ of powdery snow? OK, fine, I'll put her in 4HI. 24"+ of wet, heavy MD snow? same thing. I will literally be buying wheels based upon the sizes available of this tire.