The short answer
Ford's 2026 Super Duty manual says to change the oil when the Intelligent Oil-Life Monitor message appears, within two weeks or 500 miles. If the monitor resets early or stops working, never go more than one year or 15,000 miles on a diesel, or 10,000 miles on a gas engine, between oil changes.
Diesel trucks add fuel filters (engine- and frame-mounted) every 30,000 miles, or 15,000 miles in severe service, plus a DEF refill and fuel-water separator check at each oil change. Ford notes the diesel particulate filter may need replacement at about 250,000 miles.
The schedule, from the manual
| Item | Interval |
|---|---|
| Oil and filter | Intelligent Oil-Life Monitor; within 2 weeks or 500 mi. If the monitor fails: max 1 year or 15,000 mi (diesel), 10,000 mi (gas) |
| At every oil change | Rotate tires (dual-rear-wheel trucks: front wheels only, rears if you notice unusual wear); refill DEF; drain the fuel-water separator if indicated (diesel); inspect brakes, coolant, exhaust, steering and suspension |
| Brake fluid | Every 3 years |
| Cabin air filter | Every 20,000 mi |
| Engine air filter | Every 30,000 mi (diesel: reset the air filter monitor after replacement) |
| Diesel fuel filters (engine- and frame-mounted) | Every 30,000 mi; 15,000 mi in diesel severe service |
| Diesel engine air inlet foam filter | Every 50,000 mi; 30,000 mi in severe service |
| Transfer case fluid (4x4) | Every 150,000 mi; 60,000 mi in severe service (diesel severe: 50,000 mi) |
| Axle fluid | Every 150,000 mi (see exceptions); diesel severe service: Dana rear axles every 50,000 mi |
| Spark plugs (gas) | Every 100,000 mi; 60,000 mi in severe service |
| Accessory drive belts | Diesel: inspect at 90,000, replace at 100,000 mi. Gas: inspect at 100,000, replace at 150,000 mi |
| Automatic transmission fluid and filter | Every 150,000 mi (consult the dealer for requirements) |
| Engine coolant | First at 10 years or 200,000 mi, then every 5 years or 100,000 mi |
Towing and dual-rear-wheel exceptions
Axle and transfer case fluid don't need changing unless a leak is suspected or the assembly was submerged, with two big exceptions. During long periods of towing above 70°F, or at wide-open throttle for long periods above 45 mph, Ford calls for rear axle fluid every 30,000 miles if the axle has non-synthetic fluid (waived with the specified 75W-140 synthetic). On dual-rear-wheel commercial trucks, rear axle fluid is every 250,000 miles normally, but every 60,000 miles when you run at or near maximum gross vehicle weight.
Oil level: check it at fill-ups
Ford notes that heavy use (long periods at high engine speed, high loads, engine braking, off-road) can consume about 1 quart per 500 miles, and recommends checking the oil level at every refueling on those trucks.
What Ford counts as severe
Ford's manuals count short trips of less than 5–10 miles, temperatures well below or above average, dusty conditions, idling more than recommended and driving with a heavy load or towing as severe driving. In a Barron County winter, the cold-temperature and short-trip items describe a lot of vehicles, so follow the severe-service lines in the table if they fit how you drive.
Diesel in winter
Block heater, DEF freezing below 12°F and fuel gelling are covered in diesel trucks in a Wisconsin winter.
Booking it in Barron
Swant Graber Ford, 1697 E Division Ave, Barron, 715-537-9500. Service hours: Monday–Friday, 8:00 a.m.–5:00 p.m. (no Saturday service). Service loaners are available; ask the service department when you book. You don't have to use a dealer to keep your warranty; keep receipts wherever the work is done.
Questions
How often should I change the oil in a 2026 Super Duty diesel?
When the Intelligent Oil-Life Monitor says, within two weeks or 500 miles. If the monitor isn't working, Ford says never exceed one year or 15,000 miles on a diesel.
How often do Power Stroke fuel filters get changed?
Every 30,000 miles, or every 15,000 miles in diesel severe service, per Ford's 2026 Super Duty manual.
Does towing change Super Duty axle fluid service?
Yes, if the rear axle has non-synthetic fluid: Ford calls for a change every 30,000 miles during long periods of towing above 70°F.
When is a Super Duty DPF replaced?
Ford says the diesel particulate filter may need replacement at approximately 250,000 miles, depending on engine and operating conditions.
Next steps at Swant Graber
Swant Graber Motors (Chevrolet, Ram, Dodge): 1690 E Division Ave, Barron, WI 54812, 715-537-5657. Swant Graber Ford: 1697 E Division Ave, 715-537-9500. Search new or used inventory, or see shop near you for model-by-model answers.
