i changed my oil, and now i have a burning question... the bottles of Quaker State i used clearly exhorts the oil as providing "Proection beyond 5,000 kilometers" in yellow and black letters. Now, as an 850 owner, this oil will stay in the engine for 8,000Km. so understandabily i'm puzzled.

Does Quaker State have poor advertizing or something? did they shoot themselves in the foot? should i change this oil at 5kkm? i was told that cars that take more oil generally change their oil less simply because there is a higher volume of oil and more oil additives to consume. should i just happily drive this the 8kkm, and then change it again?