can I use 255/70R16 on my on 2wd xterra back wheels are 265/70R16 or do I have to change all 4 for different size?

For handling and safety reasons it's recommended to change all 4 if you are changing the tires size.

^x2 definelty have to change all 4

but if it's on a 2wd, why would it matter? muscle cars run skinnies up front and fatties in the back....