Question

Can you mix premium and regular gas?

Basically, you can, if your car runs fine on regular gas and premium gas. However, there's more to it.

• If premium gas is only RECOMMENDED for your car, you can mix it up.  
• But pay up for premium gas if your car REQUIRES it. 

To know whether premium gas is recommended or required for your car, check inside the fuel door for the octane level your car requires. You’ll also find it in the vehicle’s user manual.

Most cars on the roads now recommend an 87 – 89 octane rating. Anything above that (premium gas octane is > 91) is fine. Any fuel with an octane rating below the recommended range will eventually stack up a hefty service bill for your vehicle.

What happens if you use regular gas in a car that requires premium gas?  

Do not use unleaded gas in a car that requires higher octane gas. If you accidentally use regular gas or mix it with premium gas, expect a reduction in mileage and power. The worst-case scenario is engine knocking – you’ll hear the noise of premature combustion in the cylinders. The fuel won’t burn right, which is not good for the valves either. In the long term, you’ll be shelling out more during servicing due to engine damage. 

Is it okay to use premium gas in a standard car?  

If your car requires only regular gas, but the manufacturer recommends premium gas, try both and check out the difference in performance. Of course, you can stick with regular gas or dilute it with premium gas to save money. Also, it is safe to use fuel with higher octane in standard cars that require only regular gas.

In conclusion, if you have a vehicle that requires premium gas, you must continue paying high prices to keep the engine safe from damage.