Should you follow longer oil-change intervals?

Many carmakers now include automated oil-change reminders that pop up in the instrument panel, and some of them don't light up for 15,000 kilometres or more. So this adds to the debate on the benefits and pitfalls of automakers stretching out their recommended service intervals.

With the drastic reduction in distance driven by the average Canadian, thanks to the restrictions of the pandemic, some of these stretches can easily cover more than a calendar year.

No worries, right? After all, many of us are running full synthetic engine oil, so we should be able to get a premium interval for those premium prices. But for several reasons, these extra-long intervals won't make for a lasting relationship with your vehicle's engine.

First, let's address those automatic dash reminders.

Their intervals are chosen by an algorithm that takes into account engine speed, engine hours, engine load, operating temperatures and a host of other specs. But no matter how advanced or expensive your chariot is, these systems don't actually test the oil to determine contaminant levels. They're an educated guess at best.

Secondly, most of us don't “wear out” our engine oil, or expose it to such extreme operating conditions that it breaks down. The need to change it is directly related to the number of contaminants in it, which include byproducts of burning gasoline or diesel, metal filings and water.

That last one comes from the condensation that occurs in colder temperatures, and water can accumulate and mix with the engine oil under very common winter driving conditions. Short, slow runs that don't get the engine up to full operating temperatures can compound this issue.

So what is the right interval? Unless you're driving more than 20,000 km per year, an engine oil and filter change done twice a year or so isn't a bad idea. Most will do it each spring and fall.

And if you're worried about your carbon footprint, don't be. All used engine oil is recycled.

Finally, keep in mind that even with all the advancements in engine design and build, most of our vehicle undercarriages carry equipment that has seen few changes from that of 50 years ago. Some would argue that with lighter-weight materials, these suspension, steering, and exhaust components are even more susceptible than their predecessors to environmental conditions and impacts. What's this got to do with oil changes? Getting a knowledgeable set of eyes under your vehicle twice a year is still the best way to avoid nasty breakdowns or other mechanical surprises.