Octane baby, Octane !!

What is Octane ??

Why leaded or unleaded ??

Is higher Octane fuel "The good stuff" ??

Is it worth the extra money for higher Octane fuel ??


What is Octane??
To explain it simply, Octane is commonly know as a measurement of how much heat a given fuel can withstand before it ignites itself. When crude oil is removed from the ground and sent to be refined it is seperated into differant hydrocarbons. The most common ones are known as methane, propane, butane, pentane, hexane, heptane and octane. Some of these are fuels used on an everyday basis by many of us. Each one of these fuels has a differant point of which they become vapor or better known as their boiling point. This is the process that is use to refine the crude oil and seperate the carbons into many of the differant fuels mentioned. As well as each one having a differant boiling point; they also have a differant temperature of which they ignite themselves. Out of the fuels listed, Octane can withstand the highest temperature before it detonates. The octane rating we see on the pumps is the percentage of Octane that is present in the fuel. Most of the remaining percentage of fuel is Heptane. This percentage became known as the "Octane rating." Heptane has an Octane rating of 0. In the early part of 1900's during WWI there was a subsutite found that would artifically increase the "octane rating" of fuel without an actual increase in the percentage of Octane present. This subsutite is known as Tetraethyl lead. Fuel with Tetraethyl lead is simply known as leaded fuel.

Why leaded or unleaded ??
As explained above Tetraethyl lead was added to fuel as a subsitute during WWI to increase the Octane rating of the fuel. Tetraethyl lead was commonly used until the mid to late 1980's. The additive was removed from the fuel because lead is toxic to animal and human life. During the Late 70's and early 80's it was common to see fuel with the Octane rating of 104 at the pumping stations. The removal of lead from fuel drastically increased the cost of fuel. This increase in cost was because more extentive refining was required to obtain a higher Octane percentage or rating without the addition of lead. It also reduced the amount of emissions from the vehicle by utilizing catylitic converters. Catylitic converters can not be used with leaded fuels. The lead will clog them in minutes during operation.

Is higher octane fuel "The good stuff" ??
The common answer to this question is yes, many cars on the market now require a higher Octane rated fuel to operate properly. Your vehicle owner's manual will designate what Octane rated fuel is required for your perticular model. Fuels that are on the market now that have a higher octane rating and actually consist of a higher percentage of Octane, not a subsutite that increase the Octane rating. Although, because the fuels octane rating is lower does not mean that it is of lesser quality than one of a higher Octane rating. You may say define quality.
The quality that is being referred to is the cleanliness of the fuel in regards to heptane present. So, the only main differance is not the purity; one can just withstand more heat before igniting itself than the other.

Is it worth the extra money for higher Octane fuel ??
In some cases, YES !! But in others, no it is not required. Consult your owner's manual to see what the recommended Octane rating its for your model car. Performance cars tend to require a higher octane fuel than commuter cars. Cars with high mileage should use fuel that has a higher octane even though an owners manual may say it is not required. An engine's compression ratio may increase with age. This occurs when carbon deposits build up on piston domes and combustion chamber walls. An engine's compression ratio directly reflects what octane fuel is required. If a fuel is used that has a lower Octane than is required severe engine damage may occur in a short period of time. Pinging is commonly heard when the fuels octane is to low. This is really bad. If this occurs fill up with the higher Octane fuel as soon as possible. If you have a full tank, get some Octane booster at your local autoparts store.


Couldn't sleep again... Dont hold the typos, spelling and grammer against me, my head hurts alot.