Premium vs. Regular Gas: Which Grade Should You Use?
Supreme or Plus? 87 or 89? What does “regular gas” even mean?
Filling your vehicle at the pump is a pretty straightforward process but when it comes to knowing which grade of unleaded gas you should really be putting in your car, most people stall out.
That’s probably why most drivers opt for the cheapest gas available. That’s okay for a lot of vehicles but it might not be the best thing for your vehicle. Every car and truck is different and some need gasoline with higher octane levels.
Before you hit the pump again, take a moment to learn about the key differences in gas grades. The answers could go a long way toward saving you money at the pump or reducing unnecessary wear and tear on your vehicle’s engine.
What’s the difference between regular and premium gas?
When you pull up to the pump at a gas station you’ll typically see three or four different options. Usually those options are labelled in numbers: 87, 89, 91, 93, 94, and so on. At some gas stations, you might also see options like Supreme or Plus, but these will also have a number on them. So you might see Supreme 91 or Plus 94.
Forget the fancy names and just pay attention to the numbers, which refer to the octane level in each option. The higher the number on the pump, the higher the octane level. These numbers are standard across Canada, so if you’re getting Supreme 91 at one station and Synergy 91 at another, you’re getting the same grade of gas.
Why does the octane level matter? The higher octane level, the slower the gas burns, which makes it less likely to ignite prematurely—sometimes causing “knocking” or “pinging”—which can damage the engine.
What is the best grade of gas to use?
In Canada, gas with an 87 octane level is considered regular, while 89 is considered mid-grade and 91 is considered premium. At some gas stations you’ll even find ratings higher than 91. Gas with an octane level of 94 in Canada is considered Super Premium.
If you’re a new car owner, you might want to give your car the very best in care and maintenance; you might think that premium gas is always better for your vehicle, but that isn’t always the case. For many vehicles, regular gas will work fine and opting for premium won’t deliver any benefits at all so you’re really just hurting your wallet for no good reason.
Premium gas is typically recommended for use in performance engines, as their high-compression engines are more vulnerable to damage from premature ignition during combustion.
If you’re not sure what grade of gas you should be using, check the owner’s manual for your vehicle. If you don’t have your owner’s manual anymore, you should be able to find the information online—just be sure you have the correct make and model, and that you’re getting the information from the vehicle manufacturer’s website.
What about mid-grade gas?
If you’ve read this far you might be scratching your head at the existence of mid-grade gas, which in Canada is 89. You’re not alone. Mid-grade gas is a speciality option that’s required by very few vehicles on the road in Canada.
Mid-range gas has a higher octane level than regular gas, but lower than premium gas. However, that doesn’t mean it’s better for your vehicle or that it will result in better performance.
You should only use mid-grade gas for your vehicle if your owner’s manual or a mechanic recommends it.
Can you mix premium and regular gas?
If you find yourself in a situation where you accidentally mixed unleaded gas grades in your vehicle, have no fear. Gas grades can be mixed in your tank so if you topped up with regular even though you typically use premium it’s not the end of the world.
For higher-performance vehicles that require premium gas, using regular gas will slightly lower performance and increase the chances of some knocking and pinging during combustion. For non-performance vehicles that only require regular gas, topping up your tank with premium won’t result in any improved performance or efficiency. You’ll just be a little lighter in the wallet.
You’ll want to avoid mixing unleaded gas grades as much as possible but every once in a while isn’t usually an issue for most cars and trucks on the road today.
On the other hand, if you accidentally put diesel in an unleaded gas tank (or vice versa), you have a big problem on your hands. If this happens to you, don’t attempt to drive; don’t even try to start your car. You’ll have to find a professional to flush the fuel system and engine and make sure no terminal damage was done.