I have to replace my rear tires on my '21 is350 due to inner wear, but the fronts are fine. I have bridgestones on the front which i hate so I want to replace the rear tires with something else. is it ok to have a different brand for my rear tires? (AWD) . I know it isn't ideal but i don't want to replace the front 2 when they have plenty of tread left.

 

Different brands, front and rear, happens all the time.

 

Different brand is theoretically fine, but not ideal. What is more important IMO is having the same kind of tire. For example, you wouldn't run all-seasons up front and summer tires in the rear.

Personally, if I am changing tires to a new model, I switch all of them unless it's a situation where I need a tire but can't get one due to back-order or discontinuation of the tire model.

Since you're AWD I would suggest sticking to the original rear tire size, too.

 

I also replaced the Bridgestones on my '21 but, even with inner wear on the rears, my fronts were more worn. And it made sense too as the wear ratings on the fronts are much lower than the rears for the OEM set. With AWD you'll want to be careful not having too much of a circumference difference (wear) between the tires because it's hard on the AWD system.