Most modern Class 8 semi trucks run a 35,000 to 50,000 mile oil change interval, depending on engine, oil grade, and duty cycle. A Detroit DD15 Gen 5 on FA-4 synthetic blend is rated for up to 60,000 miles in line-haul service. The Cummins X15 line-haul spec runs 50,000 to 75,000 miles when using a CK-4 or FA-4 oil. Older pre-2017 trucks, and severe-duty operations (refuse, construction, mountain hauling), shorten the interval to 25,000 or even 15,000 miles. The honest test isn't the calendar or the odometer. It's the oil sample. Send a quart to an independent lab once or twice between scheduled drains and the report tells the truth about your specific truck, your specific fuel, and your specific filter program. Calendars are an estimate. Spectrometry is data.
Browse the Heavy-Duty Lube & Oil Filters collection →