And if does hurt how exactly does it?
And one more question does a cell phone really do anything to a commercial airliners equipment or are they just trying to make more money with their air phone?
Thanks.
I don’t know that much about cars, but generally speaking, cars requiring higher octane have more finely tuned engines, which require higher octane for them to perform to the optimum. On another note, I challenge you to try to get some of that gas in the car. The nozzle is too big to fit into the tank.
I don’t believe that cell phones actually cause any problems on airplanes. It is b.s. Last time they made us turn off CD and cassette players! They don’t give off any signal whatsoever!
Although the risk is virtually infinitesimal, there is a non-zero risk of a cell phone interfering with the avionics. CD players also radiate RF (due to the microprocessor-type electronics), although that’s much weaker than a cell phone.
The real reason for not allowing cell phones is that the cell towers on the ground aren’t designed for it. Normally, on the ground, your cell phone is only within the range of one cell tower (or perhaps two, if you’re on a border). If you’re flying in a plane, you have line-of-sight with many towers, and the cell software isn’t designed to handle that. In addition, as you zip along at 600+ mph, you’ll be switching cells much faster than the network is designed to handle.
There is no (valid) reason to disallow CD players and cassette recorders, though.
Arjuna34
Using low octane gasoline in an engine designed for higher octane can cause pre-ignition a.k.a. ‘Pinging’ or ‘Knocking’. You’ll hear the engine rattle as you accelerate or climb hills. Not good for the engine.
That said, modern car engines have ‘Knock’ sensors that will retard the timing at the first hint of knocking. This saves stress on the engine, but hurts performance.
You would not be able to make any calls on your cell anyways you would not be able to get a signal. Cell toers emit very little signal straight up it is a waste of power.
I don’t think 1 peice of electronic equiptment would make a big deal but if everybody was using their cell phone or CD player (which does emit electronic noise everything that has electricity flowing through it produces a signal of some strength) it would create a lot of static. Also I don’t even want to take the chance of something happening when if something goes wrong I die. I say why take chances, it proably won’t do anything but wouldn’t you feel bad if the plane crashed and killed hundreds of people just because you couldn’t live without your N’sync for a couple of minutes when the plane reached crusing altitude.
You should never use fuel with an octane rating lower than recommended. The octane rating refers to the antiknock abilities of the fuel. Using a lower octane rating can cause knocking, pre-ignition, and detonation. It can, potentially, destroy your engine.
The CAA believes that they do. But regardless of whether or not a cell phone interferes with airliner’s equipment, you can’t make a call on a normal cell phone from altitude. Your phone would be able to contact dozens of cells, and wouldn’t be able to make a connection.
Every eletric circuit gives off EM radiation.
Some, particularly high performace, engines are designed for higher octane gasoline. Lower octane gas will cause more engine ‘pinging’ (inefficient feul burn when the engine is under stress, i.e. an uphill grade), less fuel economy, and less power. The excessive pinging could cause engine damage long term, although I think the biggest drawback would be lessened performance. Any money you save in using lower octane gas will likely be offset by the lowered MPG.
As for cell phones on airplanes, I think the airlines are erring on the side of safety. Any electronic device could, theoretically, interfere with the onboard instrumentation. Has it ever happened? Not that I’m aware of. It’s similar to the cell phone bans at some gas stations. Yes, they could trigger an explosion - though the odds are vanishingly small. Someone, somewhere, established that it could happen, now the situation is foreseeable, so everyone is practicing CYA.
I read a whole thing on how car engines work at http://www.howstuffworks.com
Basically, inside the cylinder, a mixture of gas and air gets put in. This mixture is then compressed by the piston, and ignited by the spark plug. The resulting explosion pushes the piston back up. It is timed in such a way that only one piston “fires” at a given time keeping a good rotation of the crank shaft. During the compression however, energy is transferred into the gas/air mixture which can ignite the gas prematurely (before the spark plug does it). A 93 octane engine compresses the mixture more than an 87 octane engine (to get more energy). The octane rating tells how much the gas can be compressed before it ignites. If you put 87 in a 93 engine, the 87 gas will be compressed beyond it’s capacity and can prematurely ignite, throwing off the timing.
I seriously suggest reading the articles at howstuffworks related to car engines and gasoline. They’re in very simple terms, and even I understood it knowing nothing about cars.
Hope that helps. Noone really explained why the gas prematurely ignites.
I agree with this, but the performance hit (and MPG difference, as someone else mentioned) depends on the vehicle. If you have a car that recommends higher octane fuel, wait until your fuel gauge gets close to empty, then buy half a tank or so of regular. If you don’t experience any pinging, you can try a couple of tanks and compare your mileage and performance to what you were getting with premium. If you do experience pinging, fill the tank up all the way with premium, the fuel should mix with what’s already in the tank and should raise the octane up enough so you don’t have any more problems. You can then try using just one grade up (some stations near me have 4 different octane ratings, such as 87, 89, 91, 93).
Caution: IANAMOE (I am not a mechanic or engineer)
how stuff works is a great site. 
Higher octane fuel has a higher content of the heavier hydrocarbon chains (octane has 8 carbons, heptane has 7, hexane has 6, etc), and the lighter ones are more volatile. More volatile means lower vaporization temperature and lower flashpoint. As everybody stated before, engines that are rated for higher octane fuel are that way because they have higher compression ratios. Higher compression means higher temperature. Which requires a higher flash point of the fuel, otherwise you get uncontrolled combustion, also called detonation.
Detonation (ping or knock) not only causes undue wear on your engine: if it’s bad enough, it can blow a hole right through your piston or cylinder wall, destroying your engine.
Also, lower rated fuel doesn’t have a larger nozzle than higher. the only one that has a different nozzle is leaded fuel, which I haven’t seen in years.
Here’s another site that also explains about pre-ignition and detonation.
http://www.misterfixit.com/deton.htm
I think the consensus is that you’re better off if you use the reccommended grade of gas in your car.
Peace,
mangeorge
My brother is a pilot for a commercial airliner and he said that infact, electronic devices sometimes can interfere with equipment. I don’t recall everything he told me, but I do remember him saying that when CD-Rom drive spinning up in laptops was a frequent culprit.
Great Answers thanks everybody.
Also, it is helpful for you to post two separate question threads if you have two separate questions.
Thank you for your cooperation.
They ban all electronic devices so the airline employee’s do not need to make judgements about which are OK and which aren’t.
The IEEE Spectrum magazine reported a story that a man’s computer was causing a malfunction in the navigational instruments. The copilot came back and told him to shut it off. A few minutes later, the problem came back. Sure enough, the guy was working on his computer again. They made him turn it off. Some time later, on approach, the same thing happened again. They went back and confiscated the computer and had the guy arrested.
Cecil Adams on Why aren’t you supposed to use a radio receiver on an airliner? You can do the necessary extrapolation for a transmitter such as the one contained in a cell phone.
Since when do “they” ban “all” electronic devices on an airplane?
I and others have posted at length on this subject in the past. It has been beaten into the ground several times, as this is another strongly polarizing subject for some reason.
Essentially, IMPO, there is only circumstantial evidence that some electronic devices can actually interfere with aircraft equipment.
But, regardless of whatever junk science is used to justify it, one must always obey the rules of the airline, FCC, and the flight crew, as arbitrary and silly as they may seem.
Una now waits to see herself be mis-quoted here.
Not necessarily true, but close enough. Two pistons can certainly fire at the same time, it depends on the engine design.
Well, this is mostly true. While compression ratio and the mean effective pressure of the cylinder have a direct impact on the propensity to knock, you cannot draw a clear conclusion that an engine that requires 93 octane to run sans knocking is necessarily of higher compression than one that requires 87 octane. Cylinder head and valve design, spark plug placement, and mixture properties of the inlet fuel/air mixture have a large effect on this. It is certainly possible to have a 9:1 compression engine that requires only 87 octane, and an 8:1 compression engine that reqiures 93 octane.
This phenomenon is simple, yet complex to explain. Even in my grad classes on IC engines the true causes of knock were treated somewhat as a mystery. Essentially, knock can be caused by the following phenomena:
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Hot carbon deposits on the cylinder wall, cylinder head, or piston face.
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Extremely poor flow and fuel/air distribution.
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Hot spots on valves, or in the crevices of the upper piston rings.
And other, unknown causes.
Una
True, Joe. I have seen this happen personally, on a car that knocked continuously for a year or more.
Good description about fuel properties, BTW. I agree.
Well, yes and no. A knocking cylinder doesn’t produce power as efficiently anyhow as one with proper combustion characteristics will. But overall, does one really want to destroy their pistons for a little higher performance?