Search results
Results From The WOW.Com Content Network
By definition, the isomers iso-octane and n-heptane have an octane rating of 100 and 0, respectively. [86] Because of its more volatile nature, n-heptane ignites and knocks readily, which gives it a relatively low octane rating; [ 87 ] the isomer iso-octane causes less knocking because it is more branched and combusts more smoothly.
In the United States and Canada, octane ratings are in AKI, commonly shown as "(R+M)/2". All states require gas pumps to be labeled with the correct octane level and nearly all states do regular testing to make sure gas stations are in compliance. A minimum 82 octane fuel is recommended for most vehicles produced since 1984.
Octane rating is measured relative to a mixture of 2,2,4-trimethylpentane (an isomer of octane) and n-heptane. There are different conventions for expressing octane ratings, so the same physical fuel may have several different octane ratings based on the measure used. One of the best known is the research octane number (RON).
Octane is a hydrocarbon and an alkane with the chemical formula C 8 H 18, and the condensed structural formula CH 3 (CH 2) 6 CH 3. Octane has many structural isomers that differ by the location of branching in the carbon chain. One of these isomers, 2,2,4-trimethylpentane (commonly called iso-octane), is used as one of the standard values in ...
The cetane number of a fuel is defined by finding a blend of cetane and isocetane with the same ignition delay. Cetane has a cetane number defined to be 100, while isocetane's measured cetane number is 15, replacing the former reference fuel alpha-methylnaphthalene, which was assigned a cetane number of 0.
Top Tier fuels must maintain levels of detergent additives that are believed to result in a higher standard of engine cleanliness and performance as compared to the United States Environmental Protection Agency (EPA) requirement. In addition, Top Tier fuels may not contain metallic additives, which can harm the vehicle emission system and ...
Summary of the main ethanol blends used around the world in 2013. Several common ethanol fuel mixtures are in use around the world. The use of pure hydrous or anhydrous ethanol in internal combustion engines (ICEs) is only possible if the engines are designed or modified for that purpose, and used only in automobiles, light-duty trucks and motorcycles.
There’s only so far you can go with an air-throttled engine on 91-octane gasoline. In other words, it is the fuel, gasoline, that has become the limiting factor. ... While turbocharging has been applied to both gasoline and diesel engines, only limited boost can be added to a gasoline engine before the fuel octane level again becomes a problem.