Factory tire sizes

[Kent2500]

Using http://www.discounttire.com/dtcs/infoTireMath.do

 

I computed the diameter/width of all possible factory tire options (WT to LTZ) for HDs

 

245/75/17 31.47, 9.65
265/70/17 31.61, 10.43
265/70/18 32.61, 10.43
265/60/20 32.52, 10.43

 

 

[Silverado4x4]

Ok.

[jeffkirk66]

Stock tires on my 2015 Sierra 1500 4X4 are GY Wrangler SR-A 275/55-20. I'm looking for a heavier load tire and found 265/60-20 Load Range E. It is 0.6" more in diameter than the original. Will this tire fit my truck without causing problems?

[Cowpie]

Yes, it should. My 2500 came with 265/70R18 at 32.6 and I now have 275/70R18 that are 33.2. Same .6 larger like you are looking at and still plenty of room all the way around on stock height front and 2" lowered back.