- Do It Yourself Auto Repair
Myths About Motor Oil
Motor oil keeps so many machines and engines going and it always has. Today's oil is made up from 80% standard crude that every refinery produces, the other 20% is the company proprietary blends of additives and chemicals to help the engine perform and wear. Despite what your owner manual might state about frequency of changing oil, the oil experts advise every 3-5000 miles because the oil breaks down and will cause engine damage.
If you wait until the engine oil light to come on to add or change oil, then it is already too late. Engine damage has already occurred. Overfilling and underfilling is also bad for the same reason. Some people think that the oil color of black tells you when to change it, that is a myth. Many oils turn black in a few hundred miles. Go by mileage, not color.
A great myth that I thought was true is that you cannot mix synthetic with conventional oil, the opposite is true. They are totally compatible and can be mixed. Using high mileage oil in a car that is not high mileage is not good because the high mileage oil is formulated to reduce oil consumption by swelling seals within the engine. If you have already neglected changing the oil and there is some damage, switching to a more expensive synthetic will not protect your engine any better than the cheaper oil because it is too late. Synthetic oil is better than conventional oil? According to oil experts, that is not the case most of the time.
A funny myth is that by waiting longer between oil changes one can reduce harmful environmental damage. A dirty oil in a dirty engine creates much more harm to the air, so change at least every 5000 miles.