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What is the correct octane rating for 10 to 1 compression ratios Is there a chart?
Wiki User
∙ 16y ago
Depends on timing of the engine, whether the engine has aluminum or cast iron heads (aluminum dissipates heat faster, therefore allowing a lower octane), the design of the cams, and a host of other things. So no, no chart. Rule of thumb: 10:1 use 91-93 octane gas.
Wiki User
∙ 16y ago
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What does Pontiac?
Depends on compression ratios and the cylander heads but I would say at least 92 octane and full synthetic oil.
What does Pontiac eat?
Depends on compression ratios and the cylander heads but I would say at least 92 octane and full synthetic oil.
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.
Which engine is more efficient in terms of compression ratio?
For a conventional gasoline engine, the higher the compression ratio, the more efficient the engine. US passenger cars have not had very high compression ratios for about 30 years for multiple reasons. During 1970-1972, Chrysler had the highest compression ratios in US production cars, requiring the highest octane gasoline to operate properly.
Put Ron 91 petrol instead of Ron95?
Check the compression ratio of the engine: Higher ratios than 8.31:1 = Ron95 (CLC or AKI octane 90 min. :-)
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)
Most of the energy in an isooctane reaction is released in the form of?
Isooctane is an organic compound that is used in gasoline powered internal combustion engines. When it burns, it gives off heat. The heat makes gas expand and that pushes pistons down which makes the crankshaft turn. That makes the car move. Isooctane does not cause a gasoline engine to knock, which means it does not cause the gas-air mixture in a cylinder to burn before the spark plug ignites it. When an engine knocks, the mixture ignites in several places inside a cylinder and makes a knocking sound. Another chemical, heptane, causes an engine to knock. A mixture of octane and heptane is compared to another fuel to determine the octane rating of the other fuel. If the mixture is 90% octane (actually isooctane) and 10% heptane, then the fuel has an octane rating of 90. It is possible for a chemical to have an octane rating of over 100. In that case, the chemical is mixed with heptane until the percent is equal to 100% octane when the engine starts to knock. Then extrapolation is used.An engine with a 4:1 compression ratio can use a very low octane gasoline. An engine with an 8:1 compression ratio needs a high octane gasoline. An engine with a 12:1 compression ratio needs close to 100 octane.During world war 2, America went over to 100 octane gasoline and higher compression ratios. then its fighter aircraft became faster than German fighters.
Does using 98 octane in prove your gas milage over 93 octane?
NO, it does not... there has been a lot of mis-conception about this topic and being an engineer have been told several times, and have indeed mathematically shown that octane does not affect the efficiency of the engine. the octane rating is simply a rating that shows a fuels resistance to detonation and nothing more. You can confirm this by doing a little research on the Otto cycle (4 stroke standard gas engine) and understanding that when 93/98/87 octane fuel is burned, it releases the same amount of energy. the reason that this myth probably exists, is because higher performance (and higher efficiency) engines use higher compression ratios and have a tendancy to detonate lower octane fuel (knocks). also takes longer for the gas to ignite.
What is mpeg compression ratios?
100:1
Why do you use octane in vehicles?
Octane is a measurement of the combustion process. Most commonly you will see "85 87 91" octane ratings on your average gasoline pump, this of course indicates the amount of octane that, that specific product contains. The only purpose of octane is to resist detonation. What this means is that a higher octane gasoline is actually more stable than a lower rated fuel. When any kind of fuel is subject to high pressure and high heat (just like you'll find on the compression stroke of an average automobile) it becomes unstable and in some cases will spontaneously combust without an ignition source, this is called "detonation" which will make your engine sound like it's "knocking". Vehicles requiring a high octane fuel most often have engines with higher compression ratios which of course cause higher heat and higher pressures. Most common vehicles only require an octane rating of 85, octane ratings of 87 and 91 won't make your car run any better.
Which engine is the most efficient in terms of compression ratios?
Diesel engine
What is the difference between 87 and 93 gasoline?
: Fuel octane requirements for gasoline engines vary with the compression ratio of the engine; Engine compression ratio is the relative volume of a cylinder from the bottom most position of the piston's stroke to the top most position of the piston's stroke. The higher an engine's compression ratio, the greater the amount of heat generated in the cylinder during the compression stroke. Posted octane numbers on gasoline pumps are a result of testing fuel performance under laboratory and actual operating conditions. The higher the octane rating on fuel the less volatile (evaporative qualities) and the slower the fuel burns. Higher octane fuel contains more POTENTIAL energy but requires the higher heat generated by higher compression ratio engines to properly condition the fuel to RELEASE that higher potential energy. In the refining process, fewer gallons of higher octane fuels are yielded from a barrel of raw crude, thus the higher cost. If fuel octane is too low for a given compression ratio, the fuel prematurely and spontaneously ignites too early and the fuel charge EXPLODESrather than BURNS resulting in incomplete combustion. The net effect is a loss in power and possible engine damage. The operator hears an audible "knock" or "ping", referred to as detonation. Detonation may vary from a faint noise on light acceleration to a constant, deep hammering noise while driving at a constant speed. Improper timing adjustments, vacuum leaks, or excessively lean fuel mixtures may also cause detonation. Many vehicle owners believe that higher octane fuels are better for their vehicles since they are labeled "PREMIUM." The logic is that since it is a premium fuel it must be better. In reality, the premium label originates from the higher cost to refine and the resultant higher retail cost. Some refiners label their high octane fuels "SUPER." Some owners think that these fuels will make their vehicles more powerful. This is a MYTH! Only engines with high compression ratios can deliver all the potential energy from higher octane fuels! Always consult the manufacturer's octane recommendation to determine the proper octane requirements for any given vehicle. Generally, engines with compression ratios of 9.3 : 1 or less will safely operate with unleaded 87 octane fuel. Engines with higher compression ratios usually require higher octane fuels. But many modern engines will safely burn 87 octane even with a higher compression ratio. This is accomplished by way to the engine fuel/air management system. Many owners who operate vehicles designed to operate on 87 octane fuel experience ping and knock. They usually "fix" this problem by purchasing the higher priced, higher octane fuels. Most owner's manuals indicate that some light and intermittent ping is normal but that heavy or sustained ping or knock should be attended to by either purchasing the correct octane fuel or servicing the engine. Most fuel refiners blend fuels for geographic areas and adjust their blends seasonally. These blending techniques compensate for the decrease in oxygen content with an increase in altitude and compensate for volatility during the warmer or cooler seasons. Significant ambient temperature changes (40 degrees Fahrenheit) or altitude changes (4,000 feet) may cause some serious engine detonation. This problem is usually corrected by filling the tank with "local" fuel that has been properly blended for season and altitude. Bottom line is do not waste your money on a fuel with a higher octane than your engine requires. You reap no benefits, and are just wasting money.: Fuel octane requirements for gasoline engines vary with the compression ratio of the engine; Engine compression ratio is the relative volume of a cylinder from the bottom most position of the piston's stroke to the top most position of the piston's stroke. The higher an engine's compression ratio, the greater the amount of heat generated in the cylinder during the compression stroke. Posted octane numbers on gasoline pumps are a result of testing fuel performance under laboratory and actual operating conditions. The higher the octane rating on fuel the less volatile (evaporative qualities) and the slower the fuel burns. Higher octane fuel contains more POTENTIAL energy but requires the higher heat generated by higher compression ratio engines to properly condition the fuel to RELEASE that higher potential energy. In the refining process, fewer gallons of higher octane fuels are yielded from a barrel of raw crude, thus the higher cost. If fuel octane is too low for a given compression ratio, the fuel prematurely and spontaneously ignites too early and the fuel charge EXPLODESrather than BURNS resulting in incomplete combustion. The net effect is a loss in power and possible engine damage. The operator hears an audible "knock" or "ping", referred to as detonation. Detonation may vary from a faint noise on light acceleration to a constant, deep hammering noise while driving at a constant speed. Improper timing adjustments, vacuum leaks, or excessively lean fuel mixtures may also cause detonation. Many vehicle owners believe that higher octane fuels are better for their vehicles since they are labeled "PREMIUM." The logic is that since it is a premium fuel it must be better. In reality, the premium label originates from the higher cost to refine and the resultant higher retail cost. Some refiners label their high octane fuels "SUPER." Some owners think that these fuels will make their vehicles more powerful. This is a MYTH! Only engines with high compression ratios can deliver all the potential energy from higher octane fuels! Always consult the manufacturer's octane recommendation to determine the proper octane requirements for any given vehicle. Generally, engines with compression ratios of 9.3 : 1 or less will safely operate with unleaded 87 octane fuel. Engines with higher compression ratios usually require higher octane fuels. But many modern engines will safely burn 87 octane even with a higher compression ratio. This is accomplished by way to the engine fuel/air management system. Many owners who operate vehicles designed to operate on 87 octane fuel experience ping and knock. They usually "fix" this problem by purchasing the higher priced, higher octane fuels. Most owner's manuals indicate that some light and intermittent ping is normal but that heavy or sustained ping or knock should be attended to by either purchasing the correct octane fuel or servicing the engine. Most fuel refiners blend fuels for geographic areas and adjust their blends seasonally. These blending techniques compensate for the decrease in oxygen content with an increase in altitude and compensate for volatility during the warmer or cooler seasons. Significant ambient temperature changes (40 degrees Fahrenheit) or altitude changes (4,000 feet) may cause some serious engine detonation. This problem is usually corrected by filling the tank with "local" fuel that has been properly blended for season and altitude. Bottom line is do not waste your money on a fuel with a higher octane than your engine requires. You reap no benefits, and are just wasting money.
