While it is common knowledge that the people of the USA (and in particular California) worship the automobile over all other forms of transportation, there are some aspects to the operation of this sophisticated machine that are not clearly defined. I'm sure the most common misconception I run into is the issue of gasoline “grade” or “octane “. Since the cost of high octane (premium) gas is higher than low octane (regular) gas (usually 20-30 cents per gallon), it will prove to be beneficial to consumers to take an objective look at their auto’s requirements.

Let’s take a closer look at the terms I will be using to further our discussion. To begin, octane is the numerical representation of the relative speed that a fuel burns. For instance, a higher octane gas burns SLOWER than lower octane gas. Sounds backwards, doesn’t it? Why would you need to slow down the burning of the gas in your engine? Without getting too detailed, your car’s engine requires a gas and air mixture to be compressed and then ignited by a spark. Some engines compress the fuel mixture to a higher pressure than others. It turns out that these high compression engines are not only more fuel efficient, but they also gain more performance per gallon of gas used than low compression engines.

There is a limitation to this gain of efficiency from higher compression. As the high compression engine warms up, the fuel mixture has the tendency to ignite even before the spark has fired. When the gas is igniting early inside the combustion chamber, you can hear a noise similar to a can of marbles rattling around under the hood of your car. We commonly refer to this noise as “pinging”. Using the engine under a large load and low speed tends to make the problem worse. Like when you are pulling a heavy load slowly up a hill.