For most consumers, a preventive maintenance program for their car or truck consists of nothing more than an oil change. While a regular oil change is considered very important, the major point of changing the oil is to know “when” to change the oil. The interval of the oil change is often dictated by two factors: someone’s preference or the vehicle’s maintenance guide. And while the owner’s manual of your automobile may give recommendations of an oil change, that also will depend on a lot of factors as to which interval is right for you. The same can be said for the diesel engine. There are many different factors that affect the frequency of an oil change such as climate, driving style, viscosity grade, and engine condition. The best advice on performing an adequate oil change would be to have a frequent oil analysis performed.