The frequency of oil changes in a semi truck can vary depending on several factors such as the type of engine, operating conditions, and manufacturer recommendations. In general, oil changes for semi trucks should be performed approximately every 15,000 to 20,000 miles or every 6 months, whichever comes first.
For more accurate information, it is always best to consult the specific maintenance schedule provided by the truck manufacturer. These schedules take into account the specific design and requirements of the truck engine and can help ensure optimal performance and longevity.