Do octane boosters work?

[slofox]

If you really wanna increase octane - for whatever reason - then ethanol will do the job. RON of 129 (IIRC). But lower calorific value than petroleum stuff...

[Tunahunter]

I was told to run my bike on the highest octane at the pump but one day when at a Mobile station ( a rarity for me) I in inadvertantly put 91 in the tank. It ran as least as well as it ad on the higher octane. I've reverted to the higher octane but you do wonder.

[dipshit]

Had to chuckle today. I was watching 5th Gear and they had a test of most of the fuel additives available like Wynns, Nulon etc.

The octane boosters additive packages you can buy are totally different to higher octane pump gas.

5th Gear also did a test on different pump gas... http://www.youtube.com/watch?v=gQghB4asSnI

[Laava]

What about one of those in-line canisters of tin pellets that goes on your fuel line? Apparently they are really amazing at...........well.........something, I just can't remember now!
Oh yeah, they increase the cash flow thru your wallet!

[Pixie]

Avgas goes back to the second world war when a bunch of nutters were putting 2000 hp 16 liter turbocharged V12 engines in planes with 8 machine guns and went looking for a fight, and they needed very high quality, leaded, high octane fuel to run on. The specification and regulations on piston engine air craft fuel goes back to WW2.

It amazes me how many people think octane and calorific value is the same thing. Octane is the fuels ability not to ignite under compression, however as the octane goes up the flame front speed of the fuel drops. Taken to the extreme if you run race gas in a low compression vintage motor the fuel burns too slow and is still burning as it leaves the cylinder and heats up the exhaust because of the radiant energy from the still burning fuel.

Avgas is a narrow cut fuel. It has bugger all small volatile molecules, remember it burns slowly. These small molecules in pump fuel are ignited by the spark first and greatly increase ability of the fuel to be ignited cleanly and burnt by a spark. Most motors with a average ignition system just won't run well on Avgas, they spit, backfire and just run badly.

To all those folk who say their std motors run better on avgas or with some expensive dope, well sorry but "bollox". If I am wrong about this well so is Mr Honda, Mr Suzuki and Mr Yamaha who only spends about the GDP of a small country making sure their motors run as well as they possibly can on pump gas. I guess you know more than they do.

There may be some advante in adding a little tetraethyllead to pump gas because the lead might promote a little better (more complete) combustion, but only in a very few motors.

Yeah.But...but....It's high octane


(PT)

It's an idiot phrase used by people who don't understand the concepts.Like "Quantum Leap" -Originally "Quantum Jump" a phrase used to describe a change of an electron from one quantum state to another within an atom.
In real physical systems a quantum leap is not necessarily a large change, and can in fact be very insignificant.
In the popular sense, the term is usually applied to mean a large or significant change, which is thus not strictly correct.

[Pixie]

In relatively modern, high performance engines the knock sensors may reduce engine power output if the engine is starting to detonate when a fuel of too low an octane is being used.

In old high performance engines the same effect was initiated by the introduction of holes to the piston crowns while the engine was running.