Ask five drivers how often they change oil and you'll get five answers. That's because the right interval really does depend on the truck, the engine and the work it does.
Here's a practical way to set an interval that protects your engine without wasting money.
Start with your engine manufacturer
Your engine manufacturer publishes recommended oil drain intervals, usually with separate numbers for normal and severe service. That's your baseline. Many also recommend specific oil categories — see Delo vs Shell Rotella T6 for how oil choice fits in.
Adjust for how the truck is actually used
These conditions are commonly treated as severe service and may call for shorter intervals:
- Lots of idling — port queues, job sites, sleeping in the cab
- Short trips and stop-and-go city driving
- Heavy loads and long grades (Altamont Pass, Sunol Grade)
- Dusty conditions such as construction sites
- Low annual mileage where time, not miles, becomes the limit
Miles, hours or months?
For trucks that idle a lot, engine hours can be a better measure of wear than miles. Many manufacturers give intervals in miles, hours and months — whichever comes first. Track all three.
Signs you may need an oil change sooner
Some of these point to a mechanical issue, not just old oil. If you see them, book diagnostics as well.
- Oil level dropping between changes
- Oil pressure warning or unusual gauge readings
- Coolant or fuel smell in the oil
- A recent engine repair or overheating event
Make it part of a maintenance plan
The easiest way to stay consistent is to build oil changes into a preventive maintenance schedule, along with regular inspections. When you're ready, book a truck oil change — Delo SynBlend from $500 or Rotella T6 from $600, done at your truck.
Frequently asked questions
Is synthetic oil worth it for a diesel truck?
Many owners choose synthetic heavy-duty oil for its performance across temperatures and loads. Whatever you choose, make sure it meets your engine manufacturer's specification.
Can you help me set an oil change interval?
Yes. Tell us about your engine and routes and we'll help you set a practical interval based on the manufacturer's guidance.