Premium gas or regular? The differences explained

Occasionally when filling up your tank, you may ask yourself ‘Should I use premium gas?’. Here’s a primer on the differences in fuel.

What are the types of fuel?

Most gas stations sell three types of fuel (regular, midgrade, and premium). The names are often different; for example, Esso calls their premium gasolines ‘Supreme’ or ‘SUPREME+’, while Petro-Canada calls theirs ‘SuperClean’.

What do the numbers mean?

Each fuel will come with a rating. The higher this number, the more octane and cleaning agents the fuel will have. You will notice that regular gasoline has a lower number, like 87, while premium is into the 90s.

What is Octane?

Octane is a measurement that reflects a fuel’s ability to withstand compression without igniting. Your engine is designed to start in a controlled combustion, so the higher the octane number, the less chance the fuel will ignite before the spark plug can (in normal circumstances) activate your engine. A premature detonation can be damaging to the engine.

Should I use premium gas?

The best advice is to check your car’s manual. Some luxury cars and SUVs run on regular gas, while some seemingly ‘regular’ cars run on premium. Check out this detailed list for some examples. You will only likely run into car trouble if the manual specifies premium gasoline and you continue to use regular. This is because the engine was designed to use gas with a higher octane, so now it won’t operate as efficiently.