Oil Change Interval Calculator

Oil change intervals by oil type and driving style

These are the widely used starting points. Your owner's manual — or the oil-life monitor in cars that have one — is the authority for your exact engine.

"Severe service" is your manual's term, not an insult: frequent trips under ~10 minutes, towing or roof loads, stop-and-go traffic, dusty or unpaved roads, and extreme heat or cold. Most city commuters technically qualify. For engines past ~120,000 miles or built before ~2010, knock roughly 20% off the interval and check the level monthly.

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 — no adjustment. (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 everybody forgets by June — it's exactly 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's a holdover from older engines and older oils, kept alive by quick-lube marketing. Manufacturers now specify 5,000–10,000 mile intervals. The exceptions: conventional oil under severe service, and older or high-mileage engines, where 3,000–4,000 miles is still reasonable.

Can I go 10,000 miles with synthetic oil?

Often, yes — many manufacturers rate full synthetic for 10,000 miles or more under normal driving, and some extended-life synthetics claim 15,000. But severe service — short trips, towing, dust, stop-and-go — cuts that roughly in half. Check what your manual assumes before running 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 common ceiling regardless of mileage. Oil collects moisture and combustion acids even in a parked car, and short-trip driving makes 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 moisture and fuel that condense in the oil never boil off. That dilutes the oil and builds sludge — which is why "severe service" schedules, with intervals up to 50% shorter, explicitly list frequent short trips.