What do the octane readings mean at the gas pump? You usually have 3 choices at the pump: low octane, which is usually around 97, a mid-grade around 89, and supreme at around 93 octane. Technically, the octane rating is based on how stable the fuel is. These ratings are based on when fuel will spontaneously combust. This is also referred to as knock and ping when accelerating. If you have ever driven an older vehicle with a carburetor, then you have probably heard of it. The next question I usually get is, “Which one do I need to use?” With modern cars, it’s mostly a preference.
The knock and ping that I talked about earlier is not good for an engine. It can cause internal wear or damage. On a good note, on all modern cars, the computer controls ignition timing and this is also a way to control the knock and ping. When the computer detects the knock and ping or predestination, it retards the timing to get control of it. The only downside to this is you lose a little bit of power. Most people would never notice the slight loss in power. This is why your sports cars and high-end vehicles want you to use the higher octane. This gives you a little better performance. So, in simple terms, higher octane equals better performance, but if you don’t drive fast and need better performance, save your money and go with regular unleaded.
I also get a lot of questions about ethanol and if it is better than gas. The simple answer is it is not better unless you just don’t want to use fossil fuels. Ethanol is less efficient than fossil fuels. This means if you can drive 300 miles on one tank of gas, you may only be able to get 250 miles on a tank of Ethanol. Also, your vehicle must be designed to use ethanol. Ethanol is alcohol and it attracts water, so the fuel system needs to be rust-resistant. The computer needs to be able to detect alcohol due to its need to do the same job as gas. The engine oil needs to be changed sooner. For example, on a 2010 Toyota Tundra…if you use full synthetic oil, Toyota says that you can go 10,000 miles between oil changes. If you use conventional oil, you need to change it every 5,000 miles. If you run ethanol only in the fuel tank, you need to change your oil every 3,000 miles whether it’s fully synthetic or not. So, unless ethanol is cheap, it’s not worth it on the financial side of it. If you want to get away from fossil fuels, is it worth it? Come see us at White’s Automotive if you have any questions – we’re here to help you!
