Originally Posted By: max45
i was using/trying all kinds of synthetic oils, testing them by my self, but most of them what they say on a bottle is pure balooney, eg: i bout some mobile 1 ep 10w-30 and say that the oil will last around 15k, to me not truth. i did oil change, and i add some engine flush before that to clean up engine, i than i add this oil but get dirty around 4,500k miles. my car is not burning oil, only if the oil is completly black they yes what is normal. oil that i try; penziol ultra hyper, castrol edge -old formula, castrol synthec,super tech synthetic, castrol hm old formula,mobil 1 hm, napa synthetic, carquest synthetic, all of them last around 5k. this time i decide to try some schaeffer's synthetic plus 7000 10w-30, i heard good stories...
Max45, the oil getting black means it is doing its job...cleaning the engine. ALL oils will turn dark at 5k in my experience. Now, when was the last time you changed the PCV valve in your vehicle. Excessive blowby could cause engine oil to get darker than usual. Do not judge an oil by how clear it is at 5k. Just put a decent filter on there and I would highly advise you to get a used oil analysis (UOA) when you change out the schaeffers. That will give you a basic picture of how your engine is wearing, if there is any fuel or coolant getting in the oil. Cost is around $25. And check the PCV valve.