My car has about 10k miles on it, and I always keep it garaged. It's gone through 3 oil changes so far, the first two with 5W30. The third was with 10W30. I just went to my local Costco store and all they had was 5W30 oil. I bought it.
My question is, would there be anything wrong going from 10W30 back to 5W30?