What type of gas should you put in your vehicle?

gas pumps very oldEver wonder which one of the three grades of gasoline you should put in your car; regular, mid-grade, or premium. Do you think premium gas will provide better performance or are you worried about keeping your fuel system clean?

Gasoline is rated by octane. Generally, regular is 87 octane, mid-grade is 89 octane, and premium is 91 or 93 octane. Oil companies would like us to believe that higher the grade is, better your car will run. But octane ratings indicate the gasoline’s resistance to pre-ignition.

What does it means?

Engines work by compressing a mixture of fuel and air and then igniting it with a spark. One way to get more power is to increase the compression of the fuel-air mixture before burning it. These higher compression ratios can cause the fuel to ignite prematurely. This phenomenon is referred to as pre-ignition (also known as knock). Pre-ignition is bad for your engine, but it’s less likely to occur than few decades ago. Modern engines have knock sensors that detect pre-ignition and recalibrate the engine on the fly to avoid it.

What to use?

If you use regular gas in a car that requires premium, the engine will produce less power and you will get lower gas mileage. But, if you use premium in a vehicle that requires regular, you are just wasting your money. Lots of people think their cars runs better on premium gas. Frankly, the effect is largely psychological. There is no reason why a healthy engine designed for regular gas would benefit from a higher octane rating.

Of course gasoline companies advertise the additives in their expensive gas, making you believe that the more expensive the better. The truth is all gasoline contains detergents to help keep your fuel system clean. So unless your car has a label saying “premium fuel required,” it should be perfectly fine to use regular. On the other hand, if your car says “premium fuel recommended,” it means you’ll get better performance, and possibly better fuel economy, on premium gas. The age of the vehicle, or the altitude you are driving at might influence the type of fuel you need as well.