Here is my problem. I need a new rear tire and am calling different shops. Nobody has the W rated tires, but I can get Y rated one. Our stock tires are all W. Is it ok to run a higher Y rated tire with the 3 W's or should they all be the same?

 

perfectly fine. you can even run a lower speed rated tire as long as you don't exceed the recommended speed for said tire.

 

yup its ok but how worn out is the other rear tire? if its been on there a while, id recommend replacing them both so you have matching tread.