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Is propanol a good or effective fuel and why?
propanol is a good fuel because it has a high octane rating, which increases its fuel efficiency, however it is very expensive so not a common fuel.
What are octane ratings?
Octane rating is the rating given to combustable fuels that shows that fuels resistance to detonation. detonation is also known as knocks. knocks are VERY bad for an engine and efficiencies aswell, because it is simply the fuel going off before it is supposed to (premature combustion). the higher the octane rating (the pump's octane is an average of two different methods of obtaining the octane number) the more resistant the fuel will be to knocking. higher octane fuels WILL NOT increase your fuel economy, if you have observed that such is not the case, then there is another factor that needs to be considered when comparing the high and low octane fuels in your driving regemine.
How are SI engine fuels rated?
The octane rating is a measure of the autoignition resistance of gasoline and other fuels used in spark-ignition internal combustion engines. It is a measure of anti-detonation of a gasoline or fuel. Octane number is the number which gives the percentage, by volume, of iso-octane in a mixture of iso-octane and normal heptane, that would have the same anti-knocking capacity as the fuel which is under consideration. For example, gasoline with the same knocking characteristics as a mixture of 90% iso-octane and 10% heptane would have an octane rating of 90. Definition of octane rating The octane rating of a spark ignition engine fuel is the knock resistance (anti-knock rating) compared to a mixture of iso-octane (2,2,4-trimethylpentane, an isomer of octane) and n-heptane. By definition, iso-octane is assigned an octane rating of 100 and heptane is assigned an octane rating of zero. An 87-octane gasoline, for example, possesses the same anti-knock rating of a mixture of 87% (by volume) iso-octane and 13% (by volume) n- heptane. This does not mean, however, that the gasoline actually contains these hydrocarbons in these proportions. It simply means that it has the same autoignition resistance as the described mixture. A high tendency to autoignite, or low octane rating, is undesirable in a spark ignition engine but desirable in a diesel engine. The standard for the combustion quality of diesel fuel is the cetane number. A diesel fuel with a high cetane number has a high tendency to autoignite, as is preferred. It should be noted that octane rating does not relate to the energy content of the fuel (see heating value), nor the speed at which the flame initiated by the spark plug propagates across the cylinder. It is only a measure of the fuel's resistance to autoignition. It is for this reason that one highly branched form, or isomer, of octane (2,2,4- trimethylpentane) has (by definition) an octane rating of 100, whereas n-octane (see octane), which has a linear arrangement of the 8 carbon atoms, has an octane rating of -10, even though the two fuels have exactly the same chemical formula and virtually identical heating values and flame speeds.
What is the octane number?
The octane number is a measure of performance of a fuel. It is measured relative to pure isooctane which is given an arbitrary value of 100. It is possible for fuels to have an octane number higher than 100. The higher the octane number the more compression it takes for the fuel to detonate. Higher octane fuel is used usually in high performance vehicles where the engines have higher compression ratios. If the octane number of a fuel isn't high enough it can lead to engine knocking this is where the fuel detonates before the fuel is at its maximum compressive state in the engine, this can cause damage and lower performance.
What is the purpose of Octane ratings?
Octane is used to reduce pre detonation in high compression engines. The rating tells the driver which fuel to purchase and use in their vehicle as recommended by the manufacture of the vehicle.
What is high octane fuel?
Regular unleaded fuel is 87 octane. High octane fuel is any fuel higher than regular. 89 and 91 octane being the most common the consumer can buy. High octane fuel is not needed in most cars and is a waste of money if your car does not need it. It provides no benefit whatsoever in a vehicle designed to run on Regular. Octane is only a measure of how well the fuel prevents pre-detonation in a high compression engine.
Why does a high octane fuel has a less tendency to knock in automobile engine?
because the high octane fuel prevents the igniting of fuel before the starting of engine
What does octane do?
Octane rating of fuel is the quality rating the resistance of a fuel to self combust at, IE dieseling. There are three octane rating systems. The first two rate the quality of the fuel at different temperatures and the third, the one we use in the United States of America, uses the average of the two. The systems are rated starting at 0 and are theoretically limitless, with 100 being the hydrocarbon compound Octanes resistance to self combustion. As such, a compound like nitro-glycerin would be rated very low, possibly in the single digits, while a substance like, say bunker oil, would be incredibly high as it must be both highly compressed and super heated before it could combust. The reason why high performance engines need high octane fuel is that they use a high compression ratio to create higher horsepower and torque, and using low octane fuel would cause premature combustion of the fuel air mixture, some times called knocking. Wikipedia has a great article on the octane rating system that you should check out for more information.
What are the effects of octane rating?
Simple, If you engine requires 91 octane, and you put 87 in it, you will experience a degradation of engine performance, due to the lower octane having faster burn properties. If your engine requires 87 octane and you put high octane (90-91 octane) fuel into it, you will NOT see a performance boost, and may even see a slight decline in performance. What 99% of all people don't know is that High Octane fuel actually burns more slowly, than lower octane fuel. This property, allows higher compression prior to detonation, hence more performance at combustion.
What is octane number?
The amount of resistance that a fuel has to detonation. The higher the number, the less likely it is that a particular fuel will detonate in a particular engine. The number is as compared to a standard fuel (not necessarily gasoline)
Can you run high octaine fuel?
It depends on the type of engine and how high of octane you are running. Octane slows the burning of fuel, so if it is too high of octane for the engine, you will end up burning out your exhaust valves because burning fuel is being pushed out of them. 92 or 93 octane that is available at fuel pumps as "premium" fuel is ok for most engines. I wouldn't run anything over about 100 octane.
What is octane number of a fuel?
Many car engines run on gasoline. If the octane is low, the engine will knock. If it is high, the engine will not knock, which means that sometimes it will make a knocking sound as you drive along. It also might keep running when you turn off the key to the car. With high octane, the engine also starts easier. It is more expensive to make high octane fuel. Lower octane fuel gets better milage. There are two organic chemicals: isooctane and heptane. Isooctane is a good fuel for cars. It is rated at 100 octane. Heptane is a bad fuel for cars. It is rated at zero octane. When gasoline is made, they need to make a certain octane. They put the gasoline in a car engine. They then run the car with a mixture of isooctane and heptane. They find the mixture that matches the batch of gasoline. That is the octane rating of the new batch of gasoline.
