Many drivers assume that since premium fuel costs more and has higher octane, then it must be more refined or better for their engine. Conversely, it can be tempting to save at the pumps by opting for a regular unleaded gasoline rather than topping up with the expensive stuff.
Here, Michael Bettencourt, managing editor at Autotrader.ca, shares what you need to know before your next trip to the pumps.
What’s in a number? Regular octane in Canada generally falls between 87 and 89 with premium normally being offered at 91, or even as high as 94 at some stations. Octane ratings are measured in anti-knock index values (AKI). The main difference between gasolines with different octane numbers is the compression they can withstand before detonating, not the cleanliness or purity of the fuel.
Form and function. Engines are designed depending on regulations, investment and purpose. Each will feature compression ratios and design attributes specific to the intention of that power plant.
Hard-knock life. Modern premium vehicles feature anti-knock sensors, so filling up with the wrong fuel by accident won’t do much damage to the vehicle’s internals on a limited basis, but could nullify the warranty if done regularly. Engine management software will compensate by slowing ignition timing, so performance will be impacted.
Decisions, decisions. Engines that have been optimized for higher octane fuel are able to extract more power from it than an engine designed to run on lower octane. It’s always best to take the manufacturer’s recommendation. A higher-octane fuel will offer improved performance, but only if the engine is designed for it.
“It’s important to follow the specific instructions for your vehicle and do some research prior to purchasing a new one,” says Bettencourt. “Understanding the ins and outs of your vehicle and its needs will help you anticipate how much you will pay at the pumps and whether you should choose regular or premium next time you fill up.”
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