I have an 08 CTS 3.6L Non DI. It has always used oil (maybe 2 quarts in a 6500 mile change interval) between changes but at about 80k the usage increased dramatically. I am topping off a quart every 800-1000 miles. Spec is for 5W 30 synthetic which I have followed religiously. There is no sign of leak or burn at startup or when hot (I have stood in back of the car while my son revs it to 5k rpm and no smoke). I have also checked the coolant for oil contamination and it is perfect. The car runs great and has no deterioration in gas mileage or performance.
Any recommended actions? 1. Go to High Mileage Synthetic? 2. Switch to higher weight oil like 5w 40? 3. Try an additive (I don't really like that choice but respect the knowledge here).
I am going to change the plugs soon but I don't expect to necessarily find anything their either. Any advice would be greatly appreciated!
Any recommended actions? 1. Go to High Mileage Synthetic? 2. Switch to higher weight oil like 5w 40? 3. Try an additive (I don't really like that choice but respect the knowledge here).
I am going to change the plugs soon but I don't expect to necessarily find anything their either. Any advice would be greatly appreciated!
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