Oil Change Interval Calculator

Updated 15 September 2026 · SteerLog: free for one car, Pro is a one-time purchase (price shown in the App Store for your country)

Pick your oil type and how you really drive. You get a suggested interval in miles and months, and the mileage of your next change. Everything runs in your browser; nothing is saved or sent. Your owner's manual always wins.

Your car

Oil type Conventional Synthetic blend Full synthetic

Driving style Mostly highway, 20+ min trips Mixed city and highway Severe: short trips, towing, stop-and-go, dusty

Current odometer (mi, optional)

Older engine — pre-2010 or over 120,000 miles

Your interval

OilFull synthetic

Service classMixed

Or every6 months

Change your oil every

7,500 mi

whichever comes first — miles or months

Oil change intervals by oil type and driving style

These are the common starting points. For your exact engine, go by your owner's manual. Or go by the oil-life monitor, if your car has one.

"Severe service" is your manual's term, not an insult. It means lots of trips under ~10 minutes, towing or roof loads, stop-and-go traffic, dusty or dirt roads, and great heat or cold. Most city drivers count, on paper. For engines past ~120,000 miles or built before ~2010, take about 20% off the interval. Check the level each month.

A worked example

Say you drive a 2016 Civic on full synthetic, mixed city and highway, odometer at 28,450 miles.

1. Start from the table. Full synthetic + mixed driving = 7,500 miles, or 12 months — whichever comes first.
2. Adjust for reality. Modern engine, no towing, no dirt roads. So no change. (An older, high-mileage engine would drop it about 20%, to 6,000.)
3. Date the next change. 28,450 + 7,500 = 35,950 miles. At 1,000 miles a month that's about 7 months out — the mileage clock wins, so ~35,950 is the number to write down.

That last step is the one we all forget by June. It's just what SteerLog's date-plus-mileage reminders do for you.

Oil change questions, answered

How often should you change your oil?

Most modern cars on full synthetic oil go 7,500–10,000 miles between changes; conventional oil is closer to 3,000–5,000 miles. Time matters too: change it at least every 6–12 months even if the miles haven't added up, because oil degrades sitting in the engine.

Is the 3,000 mile oil change a myth?

For most modern cars, yes. It comes from older engines and older oils, and quick-lube ads keep it alive. Carmakers now set 5,000–10,000 mile intervals. The exceptions are conventional oil under severe service, and older or high-mileage engines. There, 3,000–4,000 miles still makes sense.

Can I go 10,000 miles with synthetic oil?

Often, yes. Many carmakers rate full synthetic for 10,000 miles or more in normal driving. Some long-life synthetics claim 15,000. But severe service (short trips, towing, dust, stop-and-go) cuts that about in half. Check what your manual assumes before you run the full 10,000.

Is it OK to change oil once a year?

Only if you drive few miles and use full synthetic. 12 months is the usual limit, whatever the mileage. Oil picks up water and acids from burnt fuel, even in a parked car. Short trips make that worse. With conventional oil or mostly short trips, change it every 6 months.

Do short trips require more frequent oil changes?

Yes. On trips under about 10 minutes the engine never fully warms up. So water and fuel that settle in the oil never boil off. That thins the oil and builds sludge. That's why "severe service" schedules, with intervals up to 50% shorter, list frequent short trips by name.