by Roy Todd

Created on: January 18, 2011

Changing the oil in any internal combustion engine is a required maintenance step for long service.  Most manufacturer's recommended changing it at every three months or every three thousand miles throughout the eighties and nineties.  However now with longer life motor oils, such as synthetics or synthetic blends and better filtering media in oil filters, some manufacturers are moving that recommendation to every 10,000 miles or more.  

The long and the short of it, however, is that these are JUST recommendations on how often to consider changing your oil.  The more important question is how often to CHECK your oil.  There is an oil dipstick under the hood of your car.  You should pull it out and look at it at least once every thousand miles, perhaps as often as once every gasoline fill up.  As well as looking at the fill level, you should also look at the motor oil on the dipstick.  Immediately after a change, the amount of oil stuck to the stick may be so slight that it appears almost like whater, or more accurately, clear agave nectar.  After a few hundred miles it may start to darken.  It will reach an equilibrium in most gasoline powered engines that is somewhere between amber and light brown.  This should occur by 1500 miles on the oil.  This color will range from darker to lighter with both the brand of oil, and the conditions the car is being driven in.

If you check your oil at every fill-up, or at least once every thousand miles you should get a good idea of what this color range is in your automobile's specific case.  The latest possible correct time to change your oil is when the color on the dipstick has moved on toward dark brown or black.  If the color of your oil is black, and you are not driving a diesel car, you should definitely change your oil as soon as is humanly possible.  If you are driving a diesel car, then you should always follow your manufacturer's guidelines.  As your oil may turn black far sooner, yet still be OK for your engine.

Remember, it is important to follow your manufacturer's guidelines as to the maximum time between changes be that every 3,000 miles and three months, or every year and 12,000 miles or whatever may come in between.  You should change your oil more often, not less based on the color and level on the dipstick.  If your car loses a quart of oil or more between oil changes, you may have other issues you should have a mechanic look at.  If your oil turns dark very quickly, and was not dark at the previous oil change, this could indicate that your driving has changed (pushing the car rougher, driving in a new location) but it also may indicate problems, if you are unaware of any changes that may have caused this to happen, again, take your car to a mechanic.  You may save yourself more costly repairs later on. 

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