What do all those numbers mean?

Have you ever wondered what the numbers at the gas pump really mean? Some people live by the motto; "bigger is better". In some cases that is true, but not always, particularly when it comes to gas and oil. So how do you decide? When it comes to buying gas at the pump, you need to know a little about your equipment. The owner's manual is usually the best place to start. Manufacturers put allot of effort into engineering their products and usually have a good handle on what is best for it. But, if you are like me, you put your owner's manual somewhere safe where it won't be found again until you move. So to simplify things you really only need to know one thing, is your equipment considered "high performance"? Even though you may think of your riding mower as being a "beast" it's not really a high performance engine. So what that means your mower is most likely designed to run on lower octane fuel. Where as your motorcycle or ATV is going to be much happier on the expensive high octane stuff. Octane ratings are all about the fuel's resistance to ignition. Which means the higher the number the harder it is to ignite the fuel. High compression engines need a higher octane rating so that the heat generated by compressing the fuel air mixture does not "pre-ignite". But, on lower compression engines, high octane fuel is not needed and in some cases can actually make the engine run worse. The idea that "premium" gas is better is not really true, it's just a marketing gimmick. So the next time you are at the pump and trying to decide what to get, just keep in mind what you are buying the fuel for.  But, as always, avoid ethanol fuel for your equipment and toys if at all possible.