Do you change all four of your tires?

Tires are replaced in pairs or sets of four UNLESS you have an AWD vehicle that utilizes a viscous coupling connecting the front and rear drive axles together. Because if this, it is imperative all four tires are as close to the exact same diameter as possible, otherwise, the drive axles will turn at slightly different speeds and burn the coupling up. I assume we're not talking about AWD, though. lol So in pairs or sets of four is correct.