I have a 1.4 Turbo Cruze and its been on either Mobil 1 or Pennzoil Platinum 5w-30 with 5k intervals and the engine looks like it was built yesterday. The turbo is hard on oil. The one time it was fixed under warranty and it got the GM semi-syn, you it was sheared down and had more of the consistency of 5w-20.
I know a family that has Honda Accords and their first one had 435k on Mobil 1 at 7000 mi and the second is at 340k and going with the same interval. Eventually the body just gets too bad in SE MI to be worth keeping.
Literally no need to buy Amsoil, the stuff you can buy on the shelf is totally fine.
