Understanding your motor oil: is synthetic worth the price?

You probably ask yourself the question every time you get an oil change: should I switch to synthetic oil.

Then, the price makes you cringe. Could a semi-synthetic oil meet your needs? In case of doubt, you rather play it safe. Then, you reach out for good ol’ mineral oil, thinking that you’ll change next time around.

Semi-synthetic: half and half?

It is very tempting to believe that a semi-synthetic blend contains equal parts of mineral and synthetic oils. But in fact, there are no laws to enforce these proportions. So a semi blend could as well contain only 3% synthetic oil. According to an engineer at Gulf’s, there is usually between 20 and 30% synthetic oil in a semi-synthetic blend, but we must keep in mind that it’s always up to the manufacturer.

Savings in the wrong places

Popular beliefs ruin the choice of oil and the frequency of the oil changes. The old 5 000 kilometers mentality is embedded in our habits. Yet, now the engines don’t heat up as much, they burn fuel more efficiently and they produce less emissions. A mineral oil can last up to 15 000km. For synthetic, we are looking at 30 000 to 50 000km, depending on the car and the certifications. Our “pit-stop” culture of express 20-minutes oil changes leads us to use unjustified quantities of oil. The savings shouldn’t be focused on the type of oil, but the frequency you have it changed.

The certifications

Choosing the right oil for your engine can be a puzzle. To help out, the automotive manufacturers will create certification badges. For instance, DEXOS is a standard established by General Motors (Chevrolet, Cadillac, GMC, Opel, etc). An engine oil producer can join a program and have its oil recipes certified. You can also read at the back of the bottle “meets the standards”, which means that the oil meets the automotive manufacturer’s standard but that the producer has not joined the program.

Avoid additives

A mineral oil already contains many additives that can represent up to 30% of its volume . The blend is made specifically to lubricate, resist high temperatures, clean, inhibit oxidation and is completed with an anti-foaming agent. Each recipe is balanced by the producer, according to its use. By adding an additive yourself, you might unbalance the blend and end up getting the opposite effect.