Engine oil has come a long way over the past few decades, but many engine oil myths haven't.
After more than 40 years in the lubricants industry, our team at 49 North Lubricants has heard just about every misconception imaginable, so let's separate fact from fiction.
1. You Can Never Mix Synthetic and Conventional Oil
The Truth: While it's always best to use the oil recommended for your engine, mixing synthetic and conventional engine oils isn't going to immediately damage your engine.
Most modern engine oils are designed to be compatible with one another. If you're in a situation where you need to top up your oil and only have a different type available, it's generally safe to do so.
That said, mixing oils can reduce some of the performance benefits of a full synthetic lubricant, such as improved oxidation resistance, cold-weather performance, and extended drain intervals. Once you're able, return to the correct oil recommended to you by the team at 49 North, or the manufacturer.
2. Thicker Oil Protects Your Engine Better
The Truth: More viscosity doesn't automatically mean more protection.
Engines are designed to operate with a specific oil viscosity. Using an oil that's too thick can actually reduce oil flow during cold starts, increase internal resistance, and negatively impact fuel economy. Oil that's too thin may not provide adequate protection under heavy loads or high temperatures.
Using the correct viscosity helps ensure:
- Faster lubrication during cold starts
- Proper oil pressure
- Maximum fuel efficiency
- Long-term engine protection
When in doubt, use the oil recommended by your equipment manufacturer, or contact us today to learn more about the perfect product and oil viscosity for your specific needs.
3. Synthetic Oil Is Only for High-End Vehicles
The Truth: Synthetic oil benefits almost every modern engine- not just luxury cars.
Now, synthetic lubricants are designed to provide:
- Better wear protection
- Longer service life
- Improved cold-weather starting
- Increased resistance to heat and oxidation
- Better engine cleanliness
Whether you drive a pickup, manage a fleet of heavy-duty trucks, operate agricultural equipment, or run construction machinery, synthetic oil can help reduce downtime and improve equipment reliability.
While synthetic oils typically cost more upfront, the extended service intervals and improved protection often reduce total operating costs over time.
4. Black Engine Oil Means It's Worn Out
The Truth: Color alone doesn't determine whether engine oil needs to be replaced.
Engine oil naturally darkens as it suspends soot, carbon, and contaminants. In fact, dark oil is often an indicator that the detergent additives are doing exactly what they're designed to do!
Instead of judging oil by its color, follow:
- Your manufacturer's recommended service intervals
- Your vehicle's oil life monitoring system
- Oil analysis for commercial fleets and heavy equipment
Oil can appear dark while still providing excellent protection.
5. Every Engine Needs an Oil Change Every 3,000 Miles
The Truth: The famous "3,000-mile oil change" rule is largely outdated.
Modern engines and modern lubricants have dramatically increased oil life. Many passenger vehicles now recommend oil changes between 8,000 and 16,000 kilometres, while some heavy-duty equipment and fleets safely extend intervals even further through proper oil analysis and premium lubricants.
Changing oil too frequently doesn't provide extra protection—it simply increases maintenance costs and creates unnecessary waste.
Always follow your equipment manufacturer's recommendations or consult one of the lubrication specialists here at 49 North Lubricants to optimize your drain interval.
The Bottom Line
Lubricant technology continues to evolve, but many engine oil myths continue to circulate.
Using the correct lubricant, following manufacturer recommendations, and understanding how modern engine oils perform can help improve reliability, reduce wear, and lower operating costs.
Whether you're maintaining a single pickup truck or an entire fleet of heavy equipment, choosing the right lubricant makes a measurable difference.
At 49 North Lubricants, we've spent more than 40 years helping Canadian businesses and drivers get the most from their equipment. If you're unsure which engine oil is right for your application, our team is here to help.
For support in choosing the right products for your needs, and all other lubrication inquiries, please email info@49northlubricants.com or call 1-800-463-0354.