how big of tires can i get

[ethan-333]

i have a 2004 yukon denali AWD with low miles.
im replacing the tires but thought about putting a little bigger tires. it has 17inch rims right now? could i do a bigger rim? how big of a tire could i use with 18 inch rims?
thanks

 

[massivespl]

Prly a 285/70/17
Prly a 285/65/18

 

[funky_fresh_hoff]

I have 275/70r18 tires on my Tahoe right now and they don't rub what so ever