Will higher octane gas give 50cc scooter more power?

Answer 1

High octane fuel does not have any more energy than regular fuel. All it does is contol the combustion so that more of the power can be extracted when it's being used in a high compression engine. High compression causes the fuel to burn faster, resulting in the pistons being hit hard, like a hammer, when the fuel ignites. High octane allows the fuel to burn more evenly, allowing a high compression engine to develop more power. BUT! Higher octane fuel offers no advantage to low compression engines. Added by Sneighke: A pretty good answer, but I'd like to elaborate a little. Common misunderstanding - totally implied by the oil companies in their advertising, is that high octane gas will pep up your car and is "better for it". Fact is, all the gas grades have the same protective additives. The oil companies just want to sell more expensive gas to the masses who don't know any better. As Redbeard said, higher octane gas has NO more power and actually has less. But... you may ask, "Why do high HP cars use high octane?". The answer is actually simple. "Octane" is a measure of how fast a certain blend of gasoline will burn, or more precisely, it's ability to avoid "engine knock" or detonation. The oil companies actually have a standardized, single cylinder engine that they run their gas through. If the engine "pings" or detonates, the gas has a lower octane. So if high octane gas has less energy by volume, why do we need it? Again the reason is suprisingly simple. High performance engines - as in fast cars like Cobras, Corvettes, LS1's, etc., are tuned to make much more power than the usual car. The main ways of doing this are A) designing the engine to have relatively higher compression ratios ("normal is around 8:1, while "performance" is closer to 10:1 or more, and B) running the engine at higher speeds. However it's the cylinder pressures which dictate the need for the correct octane. It's "A)" which is the major issue. High compression/high HP engines will suffer from major detonation due to the very high compression ratios (cylinder pressure) if the gasoline ignites too easily. In fact, engine knock is caused by the mismatch in timing between the spark, the piston position, and the speed of "explosion" [the wavefront] of the gasoline. Allowing any engine to run with constant detonation will kill it much faster than normal and possibly, very quickly. The solution is to use a high octane fuel which as Redbeard correctly pointed out, burns slower, or in other words, explodes less easily, but also has less energy for a given amount of fuel. In the end, though you might be putting the lowest energy, slowest burning gas in your tank (which the lovely oil companies charge us MORE for), when used in a high compression engine tuned for high octane, you end up with more power at the wheels. In other words, the more extreme the engine design in terms of compression/cylinder pressure, and spark timing, the higher the octane (slower burning) is needed in whatever fuel is being used. As an extreme example, Indy cars, and funny cars - using huge superchargers to force air into the engine which raises the effective compression or cylinder pressures - make huge amounts of power. As a result, they need a fuel with a very high octane rating; a "very slow burning" fuel. One example of a high octane fuel would be simple EToH, or ethanol... Vodka if you will, though methanol can also be used. Even though alcohol has roughly 2/3 the amount of energy as gasoline, the cylinder pressures in engines needing high octane, more than make up for that loss of energy and can produce very high power outputs. I'd imagine if someone accidently filled up an Indy car with "low-grade", 87 octane gasoline, they'd be rewarded with nice engine block full of shrapnel and a totally destroyed engine. So, bottom line: Your 50cc scooter not only does not need anything higher than "regular" gas, it will also run better and scoot better compared to running "premium" gas.

Added by DSisdawayilive: I'm just adding some more. I myself, dsisdawayilive conducted an experiment. This experiment proved that a higher octane gasoline burns slower resulting in a longer run time of the engine. You may get a little bit better mileage with Premium. My personal recommendation is to get Mid-Grade gasoline because the results are very close to premium. For any questions email me at: DSisdawayilive@gmail.com