This is primarily because fuels contain an oxygenate that prevents knock by adding oxygen to the fuel. This oxygenate is commonly referred to as octane. At most retail gasoline stations, three octane grades are offered, 87 regular , 89 mid-grade , and premium. The higher the octane number, the more resistant the gasoline mixture is to knock. Doing so would increase vehicle efficiency and lower greenhouse gases through decreased petroleum consumption.
In the early 20th century, automotive manufacturers were searching for a chemical that would reduce engine knock. In , automotive engineers working for General Motors discovered that tetraethyl lead better known as lead provided octane to gasoline, preventing engine knock. While aromatic hydrocarbons such as benzene and alcohols such as ethanol were also known octane providers at the time, lead was the preferred choice due to its lower production cost.
Leaded gasoline was the predominant fuel type in the United States until the U. Environmental Protection Agency EPA began phasing it out in the mids because of proven serious health impacts. Early in its use as a fuel additive, health concerns were raised regarding the use of lead in gasoline.
In , 15 refinery workers in New Jersey and Ohio died of suspected lead poisoning. As a result, the Surgeon General temporarily suspended the production of leaded gasoline and convened a panel to investigate the potential dangers of lead use in gasoline.
Despite these warnings, the Surgeon General set a voluntary standard of lead content, which the refining industry successfully met for decades. It was not until the s, following extensive health research, that the devastating health impacts of low-level lead exposure were established. The health impacts of lead exposure in children include anemia, behavioral disorders, low IQ, reading and learning disabilities, and nerve damage. In adults, lead exposure is associated with hypertension and cardiovascular disease.
Prior to the lead phase-out in gasoline, the total amount of lead used in gasoline was over , tons per year.
Congress passed the Clean Air Act in , setting in motion the formation of the EPA and, ultimately, the removal of lead from gasoline. EPA estimates that between and , 68 million children were exposed to toxic levels of lead from leaded gasoline alone. The phase-out of lead from gasoline subsequently reduced the number of children with toxic levels of lead in their blood by 2 million individuals a year between and The EPA is formed and given the authority to regulate compounds that endanger human health.
Lead damages the catalytic converters used in these new vehicles to control tailpipe emissions. An octane rating is simply a measure of how heat resistant a fuel is in order to prevent knocking. If you hear knocking, you could be using the wrong octane for your ride. Which octane rating should you use? You should always use at least the minimum octane rating recommended by your vehicle manufacturer.
Using a lower-octane fuel than required can cause knocking and will prevent your vehicle from meeting its stated fuel economy. West, B. Huff, L. Moore, M. DeBusk, and S. Department of Energy and the U. Environmental Protection Agency. DOE and the U. Toggle navigation. Selling your car? We can help you advertise its mpg. Vehicles produce about half of the greenhouse gases from a typical U. We can help you calculate and track your fuel economy. MPG estimates from drivers like you!
Answers to frequently asked questions about octane. Enter vehicle or phrase. Selecting the Right Octane Fuel What is octane rating? What octane fuel should I use in my vehicle? Why do some manufacturers require or recommend the use of higher octane gasoline?
What if I use a lower octane fuel than required for my vehicle? Will using a higher octane fuel than required improve fuel economy or performance? What does octane do? It just prevents the air-fuel mixture from igniting before the spark plug does it. Firing the air-fuel mixture at the proper time gives you the maximum power your engine was designed to get.
Using higher-octane gasoline than your engine is designed to utilize is only wasting your money. Shop Now. Octane Ratings Posted by: Bell Performance. You may be interested in these other posts: Does oil change affect performance? What makes gas prices change? Octane and Mileage: Does low octane hurt your gas mileage? Share This Article!
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