Article on octane is wrong

[Vashner]

Came across this while looking at the NBC NO streaming video.

This guy teaches automotive and does not even know what octane is?

ahahah "for pinging". Actually it's per engine design and you should pump what your vehicle manual says per your engine. Super is used for higher compression vehicles. Only a few engines require Super or medium 90 octane.


http://www.wdsu.com/6onyourside/4308417/detail.html

NEW ORLEANS -- Does it matter where you purchase your gasoline, and does buying high-octane fuel give you better gas mileage?


With fuel prices rising almost daily, experts say it's important to separate the facts from the myths.

In her latest outing, WDSU NewsChannel 6 consumer reporter Stephanie Boswell found regular unleaded as high as $2.05 a gallon and as low as $1.99.

With such a variety of fuel prices to choose from, why do some consumers pay the higher price? Because some believe fuel at the big name gas stations is better.Story continues below ad

Randy Trailor teaches motor vehicle technology at Delgado Community College. He said whether you buy from S or Spur, the fuel at local gas stations comes from the same refinery.

"The only difference is some of the additives they're putting in the fuel," Trailor said. "It comes from the same hole in the ground at the refinery where it was processed."

What about the octane level? There's a widespread perception that the higher the octane level you put in the car, the better its performance. Trailor said that's a myth.

"All the octane rating is is an anti-knock additive that they rate it as taking away engine ping and a little rattling noise, and does it burn even enough," Trailor said.

Another interesting fact is that now that gasoline prices have reached the $2 mark, some stations are running out of the number two for their outdoor signs.

[Clandestino]

from what i have read, engines nowadays are so bad ass they can handle lower octanes.. even the ones who say, Premium only..

[SWC Bonfire]

Somewhat correct. A lot of modern, computer controlled engines can handle lower octane gasoline because they have knock sensors. This re s the timing (and possibly fuel delivery) and results in power loss, but a lot of times it is not noticable to an everyday user. Not only high-compression engines require higher octane fuels; some engines use computer "chips" to simply advance the timing and fuel delivery curves to create more power over a "standard" engine. They two are mechanically identical, but one requires higher-octane fuel to perform as rated. The performance difference becomes more noticable during climbing at al udes, in high heat, and when towing.

Im not a refiner or organic chemist, but my understanding is that octane is a good approximation of the amount of energy in gasoline (cetane in diesel). It doesn't necessarily mean that the fuel actually contains 100% octane per se, but is an equivalent energy of a certain amount of octane.

[Vashner]

Yea I think in a pinch you can run unleaded in something like a Celica GTI VVTLI engine (highest horsepower per liter) but the manual calls for 91+

I have no idea what it would do in the long run...
But my problem was that guy and article make people with 87 vehicles think
that wasting money on higher is gonna help. It's gonna run hot and maybe mess up other systems in the engine system.. (99.% of all vehicles non diesel) run on basic Unleaded.

[SWC Bonfire]

Well, you get autodetonation, which is pinging. If the computer didn't respond by correcting it, you put a lot of wear on the engine. Basically, a ping is when the gas explodes while the piston is still coming up, you can imagine what impact that has.

[SWC Bonfire]

Here is a good short article:

http://auto.howstuffworks.com/question90.htm

[SWC Bonfire]

cessnas run on 100

I think that the octate rating of aviation fuels is actually different that that of automotive fuels, so 100 octane doesn't mean 100% octane exactly.

[SWC Bonfire]

Well, I looked a little bit and it does contain the same amount of energy as 100% octane fuel.

This explains why it is used for racing (off-road use in high-compression engines).

[Vashner]

LL100 is the general aviation fuel. They have high compression engines and need more boom.

[sickdsm]

your forgetting high octane on TC/SC cars. Towards the end when i stopped really caring about performance i ran 87 octane on my slightly modded GSX for about a year.

[The sone]

my car runs on beer backwash and old dishwater...the stink is sumthin fierce but the price is right!!