Synthetic vs Conventional Oil: Which Does Your Car Need?
If your owner’s manual requires synthetic, use synthetic. If it allows either one, synthetic is usually the better fit for newer engines, turbo vehicles, heavy commuting, and winter cold starts around Etobicoke. Conventional still works for some older, simpler engines if you change it on time. The real mistake is guessing on oil type or stretching the interval because the car seems fine.
The short answer
For most late-model daily drivers, synthetic is the better fit. It handles cold starts better, stands up to heat better, and usually gives you a longer interval range.
If you’re trying to decide which oil your car needs, use this quick rule:
- Use synthetic if the manual requires it.
- Lean synthetic if the engine is turbocharged.
- Lean synthetic if you do lots of short trips, idling, or winter city driving.
- Conventional can be fine if the manual allows it, the engine is simpler, and you change it on time.
Oil choice and oil-change timing go together. A cheaper oil stops being cheaper if you run it too long.
What synthetic changes
The practical difference shows up in two places: cold starts and heat.
Synthetic oil stays more fluid in the cold, so it reaches the engine parts that need lubrication faster after startup. That matters in Toronto-area winters, where short trips and cold starts stack up for weeks at a time.
It also resists heat breakdown better. If your week looks like Highway 427 traffic, long idling, and summer stop-and-go driving, synthetic usually keeps its protection longer.
| What matters | Synthetic oil | Conventional oil |
|---|---|---|
| Cold starts | Flows better in low temperatures | Usually thickens more when cold |
| Heat resistance | Holds up better in hotter running conditions | Breaks down sooner under heavier heat |
| Turbo use | Usually the better fit | Often not ideal unless the manual allows it |
| Typical interval | Roughly 10,000 to 12,000 km | Roughly 5,000 km |
| Cost up front | Higher | Lower |
Short-trip driving matters too. If the engine barely gets fully warm before you shut it off again, the oil has a harder life than it does on a steady 40 km highway run.
When conventional still makes sense
Conventional oil still has a place. You do not need to pay for synthetic if the vehicle does not call for it and your driving does not push the oil very hard.
It can be a sensible choice when:
- the owner’s manual allows conventional oil
- the vehicle is older and naturally aspirated
- you still change oil on a short schedule
- keeping the upfront service cost down matters
Age alone does not decide this. A 15-year-old car may still be fine on synthetic if that is what the manual calls for, and an older non-turbo commuter may still be fine on conventional if the manual allows it.
For a simple daily driver that gets regular service, conventional can still be the practical budget option. The catch is the shorter interval. You need to stick to it.
Which engines should use synthetic
Turbo engines are where the answer gets much clearer.
A turbo runs hotter than a basic naturally aspirated engine, and that puts more stress on the oil. That is why many turbo vehicles either recommend synthetic strongly or require it outright.
Synthetic also makes sense for:
- engines with automatic start-stop systems
- vehicles used for delivery or rideshare work
- commuters who spend a lot of time in traffic
- newer engines with tighter oil-spec requirements
If your vehicle has high kilometres, do not assume you should switch away from synthetic. A higher-kilometre engine still needs the oil grade and manufacturer spec the manual calls for.
That includes common grades such as 0W-20 and 5W-30. The viscosity matters, and the approval spec matters too. Two bottles can show the same grade on the front and still not be the right oil for your engine.
How often should you change it
For most drivers, the rough guide is simple:
- Conventional oil: about 5,000 km
- Synthetic oil: about 10,000 to 12,000 km
Treat that as a starting point, not a dare. The owner’s manual comes first, especially if your vehicle has a maintenance monitor or a required oil specification.
Some driving habits shorten either interval:
- repeated short trips
- long idling
- delivery driving
- winter city commuting
- heavy stop-and-go traffic
- carrying heavier loads regularly
If that sounds like your week, use the shorter end of the range. Frequent short winter trips can be hard on oil because the engine starts cold, may not fully warm up, and gets shut off again.
And check the oil level between services now and then. Old oil and low oil are different problems, and both can get expensive.
What the $69 and $99 oil changes include
If price is part of the decision, here is the straight answer.
A conventional oil change starts at $69 for a standard vehicle with up to 4 L of oil. A synthetic oil change starts at $99 for a standard vehicle with up to 4 L.
Both include:
- oil for the service selected
- a new OEM-spec filter
- a multi-point fluid and belt check
- tire-pressure adjustment
- responsible disposal of the old oil
If the vehicle takes more than 4 L, or it is a pickup, large SUV, or another model with different oil requirements, any price change is confirmed before the work continues.
You can check the oil change service page or the full pricing page if you want the details before booking.
If the manual requires synthetic, the choice is made for you. If it allows both, you are balancing a lower upfront price against better cold-weather performance, better heat stability, and a longer interval range.
FAQ
Can I switch from conventional to synthetic oil?
Yes, in many vehicles you can switch from conventional to synthetic oil if the oil grade and manufacturer spec match the owner’s manual. The label on the bottle matters less than using the exact grade and approval the engine calls for.
Does synthetic oil cause leaks in older cars?
Not by itself. Synthetic oil does not normally damage seals, but existing wear or seepage may become more noticeable after a change.
Should I use synthetic oil in a high-kilometre engine?
Yes, if the owner’s manual calls for it, a high-kilometre engine should still use the correct grade and spec. High mileage does not cancel the manufacturer requirement.
Can I wait longer just because I use synthetic oil?
Only within the interval your manual allows. Synthetic usually lasts longer than conventional, but it does not cancel severe-use conditions or routine level checks.
When to book the shop
If you’re still not sure which oil your car needs, call or text 416-856-4295 with the year, make, model, and engine. We’ll point you in the right direction. If you already know what your vehicle takes, walk-ins are welcome for oil changes when a bay is open. For weekends and late afternoons, it is better to book ahead.
Rexdale Auto Detailing is at 2082 Kipling Ave Unit #1, Etobicoke, ON M9W 4J9. Hours are Monday to Friday 8:00–6:00, Saturday 8:00–3:00, and Sunday 12:00–3:00. Rickey answers the phone, so if your vehicle needs extra oil or a different setup than a standard 4 L service, you will hear that before the work continues.