Premium Versus Regular Gas
The dictionary defines premium as something of superior quality or value. Premium gas is often given as an example of the word's usage. Premium gas costs more than other gas. We expect the best value from something that's the most expensive. It makes sense that premium, the highest quality gas, should be the best choice for your car. Strangely enough, that's not necessarily true.
At the gas pump, there are usually three options for gas: regular, super, and premium. Respectively, they each have different octane ratings, typically 87, 89 and 91. An octane rating refers to the fuel's ability to burn smoothly in a controlled manner.
Does your car need premium gas? The answer can be found in your car's operating manual. Usually, the manual won't state that your car requires premium gas, so, any other type of gas will be sufficient. The usage of premium gas is typically reserved for high performance cars. Even if you own one of those, buying premium gas may not prove to be absolutely necessary, depending upon your point of view regarding performance.
The manuals of some high performance cars state that premium gas is required. If your manual doesn't say required, then it might say recommended. Recommended means that the car doesn't need premium gas, but it'll behave better if it runs on premium. High performance cars prefer a high octane gas. Using premium gas, their engines can run at the highest compression ratio, thereby giving them more power. Only a handful of high performance engines are designed to operate exclusively at a higher compression ratio. Without premium gas, their powerful engines may tend to 'knock' or misfire. Most other high performance cars have a computer-controlled knock sensor that can compensate for the usage of lower octane gas. Those cars can use regular, super or premium gas. If premium gas is used instead of regular, the maximum increase in acceleration power is about 5 percent. You'll have to decide if that additional amount of power is worth paying an extra 10 to 30 cents per gallon. If you're unsure about what to do, you could compromise and choose the middle octane (super gas).
Regardless of what car you have, knocking can also occur if harmful carbon deposits have built up in your engine. This degradation in performance is especially prevalent in older cars that use regular gas. Some experts believe that using premium gas can improve performance. Others disagree, also stating that the engine will wear out faster if premium gas is used. All of the experts agree that a serious carbon deposits problem should get repaired as soon as reasonably possible.
Expert opinions vary widely about the effectiveness of using premium gas in cars that weren't designed for its usage. If your car's operating manual says that it's recommended, you'll have to decide if the extra power is worth the extra money. In summary, you only have to use premium gas if your manual says that it's required.
