This will be on my son's 97 Cavalier.My 5 Gal container has been used up and I hve decided to go with the 10W-30 Blend for the next time. I'll be changing tomorrow and it will have somewhere around 12 K miles on it. It went a little further than I wanted to go. It will be interesting to see how the Blend does in comparison to the Pure Syn. I wanted to put in 5W-30 but I ran out of time so it will have to be the 10W-30. I called up the Schaeffer's man and asked him which was more shear stable-he indicated there was no difference. He did indicate that it should be good for a 9K drain interval. It's amazing that they go out on a limb and actually make that statement.