How Often Should You Change Your Oil? A Canadian Answer

How often should you change your oil, really?

Go by your owner's manual or the oil-life monitor, not the sticker a quick-lube shop put on your windshield. The old every-5,000-km habit comes from older engines and older oils. Plenty of newer cars are rated for longer than that on the normal schedule, and some oil-life systems will stretch to around 16,000 km or a year before they ask for service. Ford's own oil-life FAQ uses 16,000 km or 12 months as the outer window.

Two rules sit on top of whatever number the manual gives you. First, time counts, not just kilometres. GM, for one, says the oil and filter must be changed at least once a year even if the oil-life system hasn't asked for it, so the car that only goes to church and the grocery store still needs its yearly change. Second, the normal schedule assumes normal driving, and very little winter driving around here is normal by the manual's definition.

The straight answer: find the severe-service schedule in your manual and ask yourself honestly whether it describes how you drive. For many Greater Moncton drivers, for at least half the year, it does.

What counts as severe service (and why Moncton winters usually qualify)

Severe service sounds like logging roads and pulling a boat. It isn't. Picture a normal January week: a short run from Dieppe into downtown Moncton at -15 °C, ten minutes of remote-start idling in the driveway first, brine and slush on Wheeler Boulevard, a quick trip to Champlain Place and home. That's three or four severe-service boxes ticked before Friday.

The reason is moisture. An engine that never fully warms up can't cook off the water and unburned fuel that collect in the oil on every cold start, so the oil wears out faster than the kilometres suggest. On short-trip winter cars you'll sometimes find a beige, mayonnaise-like gunk under the oil filler cap. That's usually condensation mixed with oil, and it's the engine telling you it isn't getting long enough drives. If it's heavy and keeps coming back after longer highway runs, have the cooling system checked, because coolant in the oil can look similar.

Idling is the sneaky one. Natural Resources Canada's guidance is that even on cold winter days, two to three minutes of idling is usually enough warm-up for a modern engine, and the best way to warm a car is to drive it. Ford's oil-life FAQ gives the example of a heavily idled vehicle calling for an oil change at about 7 months and roughly 6,400 km instead of a full year. A block heater helps too: NRCan notes it warms the engine and its oil so it reaches operating temperature faster, and two hours on a timer is enough.

Hyundai's owner's manual is a good example of the fine print most manuals carry. Its severe-usage list includes:

• Repeated short trips of less than 8 km in normal temperatures, or less than 16 km in freezing temperatures
• Extensive idling or long stretches of low-speed driving
• Driving on salt-spread roads, or in very cold weather
• Heavy traffic and frequent stop-and-go driving
• Towing a trailer, using a camper, or carrying loads on the roof
• Using an engine oil that isn't the type the manual recommends

Can you trust the oil-life monitor?

Mostly, yes, with two catches. Most oil-life monitors don't actually test the oil. They estimate its remaining life from how the engine is used. Ford says its system weighs engine temperatures, idling, towing and other driving habits. That makes a monitor smarter than a fixed sticker, because it does notice short cold trips and long idles.

Catch one: it doesn't know how much oil is in the engine. Hyundai's manual says plainly that its oil-life system assumes the oil is being topped up normally, and tells owners to check the level regularly because engines use some oil between changes. A monitor showing 40% life on an engine that's a litre low is still a litre low.

Catch two: it only works if it's reset at every change, with the right oil in. If the last place forgot to reset it, or someone reset it without changing the oil, the percentage on your dash means nothing. When you buy a used car, assume the monitor is lying until you see a receipt.

Synthetic vs conventional oil: which do you need?

The one your manual specifies. Many newer engines call for a full synthetic in a thin grade like 0W-20, and on those cars synthetic isn't an upgrade, it's the requirement. Hyundai even counts running a non-recommended oil, including mineral or semi-synthetic oil, as a severe-usage condition. The oil also has to meet the spec printed in the manual or on the filler cap. Many GM engines, for example, call for a dexos-approved oil.

Where the manual gives you a choice, synthetic suits a Maritime winter. The first number in the grade (the 0 in 0W-20) describes how the oil behaves cold, and synthetics generally flow better on a hard cold start and hold up better to the short-trip, stop-and-go use described above.

What synthetic doesn't do is give you permission to ignore the schedule. Use the interval your manual or monitor gives you, and if you're on the severe-service schedule, stay on it.

How to check your oil on the dipstick

Two minutes, once a month and before any long drive. Some newer cars have no dipstick at all and show the oil level on the dash instead; the owner's manual explains how to read it.

Know the difference between the oil-change reminder and the red oil-can light. The reminder means book a service soon. The red oil pressure light means pull over somewhere safe and shut the engine off, which is what GM's own guidance says, because running an engine with low oil pressure can damage it.

If you're adding oil regularly, note how much and how often. For a standard dipstick check:

• Park on level ground. A sloped Riverview driveway will give you a false reading.
• Shut the engine off and wait a few minutes so the oil drains back down. Your manual will say whether it wants a warm or cold check.
• Pull the dipstick (usually a yellow or orange loop), wipe it clean, push it all the way back in, then pull it again.
• Read where the oil film ends between the two marks or holes. If it's near the bottom mark, top up with the correct oil a little at a time and recheck.
• Look at it. Dark oil is normal once it's been in a while. Milky, gritty or smelling of gas is not.

What a proper oil service includes (and why records matter)

An oil change is more than pulling the plug and pouring in new oil. A proper one means the old oil drained fully and a new filter every time, the right grade, spec and amount for that engine, checked on the dipstick afterwards, a new drain plug washer where the car uses one, and the plug tightened to spec rather than as tight as someone can get it. The oil-life monitor gets reset. And while the car's open, someone should look underneath for leaks and check the other fluids, the belts and the tire pressures. That last part is where an oil change earns its keep, because it's often the only time someone who knows what a weeping gasket looks like gets under the car.

Keep records. A folder of receipts or a note on your phone with the date, kilometres and what oil went in is enough. It keeps you on schedule, and if an engine problem ever turns into a warranty conversation, or you sell the car, proof of regular oil changes is the first thing people ask for. If you're buying used, ask the seller for it before you hand over any money.

Used oil should never end up behind the shed. New Brunswick has had an industry-run oil and glycol recycling program since 2014, overseen by Recycle NB, and it takes used oil, oil filters and oil containers without a recycling fee at the drop-off.

If you're in Dieppe, Moncton, Riverview or Shediac, we do oil services in your driveway or an approved work parking lot. Send us the vehicle and your postal code through the form, or call or text (506) 871-0669, and we'll confirm the oil it needs and the price before anyone drives out.