Text by Steven Bochenek.

Oil is an essential part of your vehicle’s engine ecosystem, lubricating the many fast-moving parts and ensuring peak performance. You have choices about what type of oil to put in your vehicle—the variables being the type of oil and its viscosity (in essence, the liquid’s thickness). Read on to find out how different oil formulations can impact cost, vehicle performance and the environment.

Types of oil

Requiring the least amount of production, conventional oil is refined from crude and mixed with additives.

Synthetic oil is composed of chemically treated petroleum components and synthesized additives—an intricate laboratory process—all to enhance chemical stability. Requiring more steps in production, it’s costlier (by a factor of about two to four times, according to Consumer Reports), but boosts engine longevity and performance.

Given that production intensity affects price, blended oil is the Goldilocks solution, lying somewhere between the first two choices. Cheaper than fully synthetic oil, it also provides fewer of its performance benefits.

Environmental impact

A non-renewable fossil fuel, crude oil requires extracting, transporting and refining. When it’s refined into conventional oil, the remaining impurities are more harmful than synthetics (and blends) when small amounts burn during your engine’s operation. Many synthetic oils are made of re-refined oils, whose production includes extra filtration to reduce contaminants. This means synthetic oils are arguably “cleaner,” while also improving fuel efficiency. Keep in mind, however, that more intensive production also consumes energy. In the end, cleaner and longer operation give synthetic oils an environmental edge over conventional oils.

Performance

In cold Canadian winters, synthetic oils retain better fluidity than conventional oils and blends. In extreme heat, they resist degradation. Synthetics also clean residual gunk collecting throughout your engine.

How to talk to your mechanic about oil

Trust your mechanic, a licensed expert, and explain how you generally drive. Tell your mechanic how far and often you commute. Do you tow, accelerate and/or brake hard? Do you leave town regularly? Drive on rural roads or mostly highway? Such details inform a mechanic’s expert advice regarding what oil grade to use and when to change it.

Most vehicles require an oil change at around 8,000 to 12,000 km, but some can go to 20,000 km. With such variance, don’t be afraid to ask your mechanic questions. And check your owner’s manual for the manufacturer’s recommendation.

Questions about vehicles? Email autoadvice@caasco.ca or call 1-866-464-6448 with questions for our experts.