Been reading for a while and the concensus seems to be to use 10-30 instead. Is the 5-30 just for the manufactures to meet tougher gas mileage requirements? The service manager at Saturn cautioned me against using 10-30 because he said the timing chain had small holes leading to it and they have seen chains break because of oil starvation. Hence his idea that the thinner 5-30 be used. This engine is I suppose hard on oil and I am currently going through three treatments with Auto-RX to hopefully decarbon the stuck oil rings. (It is drinking 3 quarts in 3K) If this thing will stop using oil I had planned on using M1 10-30. If it still drinks then I will use good cheap dino like the fav. Castrol GTX. Should I be fearful of using 10-30 dino oil?