I live in Norcal and have access to 100 octane gas at a VP Racing Gas Station. 100 octane is usually reserved for dirt bikes, atvs, race bikes and high compression turboed cars, but at $7.45 a gallon would you put it in? Does anyone have experience with this octane? What are the benefits?

 

none unless you have a higher compression engine with some aggressive timing that needs more resistance to detonation, which in that case is not a benefit, it's a requirement.

 

i'm sure there's 'some' improvement, but hardly worth that premium, that's just me...

if you're super curious, you can always dyno before and after and let us know!! lol

 

fuel is not a benefit, it's essential item and had to be matched to the requirements of the engine. i do some engine building and playing around with components and if you have too high of an octane for a given motor, you could actually hurt performance a little as you won't be able to obtain the ideal combustion parameters to properly burn the fuel. 100 octane isn't all that high so I assume you won't see any improvement but probably won't lose any either, but there are no benefits.

but again, fuel is something that has to be matched to the particular motor. the motors I build are designed from the ground up around 110 - 112 octane and run a 14:1 to 15:1 compression... if I ran 93 in them, they'd explode. likewise, if you ran 110-112 in an 8:1 motor, you wouldn't obtain ideal combustion and probably lose performance... but at least it wouldn't explode... lol

 

If that 100 octane has any lead in it, it will ruin your cats.

 

true, but since it's at the pumps, i'd imagine it's unleaded, but good point Jeff.

 

IT'LL TURN YOUR CAR INTO A MAD FAST RACE CAR YO!



Actually, the higher the octane the LESS combustible the fuel.

You'll lose power AND fuel economy, and possibly gum up your injectors.


I'd actually be curious to see if 91 or 93 octane makes more power in our cars. Hmmm....

 

I'm no scientist/chemist but if I understand octane correctly, higher octane fuels does NOT equal a more powerful fuel, it equals a greater tolerance preventing the fuel from igniting at lower tempatures - a higer temp detonation point (flash point) for higher octane fuels. Someone needs to dyno our car with different grades of fuel to confirm this. Higher octane fuel is needed in high compression engines to prevent knock. There is no other benefit, as I have been told. The power of packaging.

 

The engine management system in our vehicles will apparently adjust the timing to cope with the variations in octane; it would therefore not be worthwhile to use 100 octane at US$7.25+ per gallon.

I have a hotrod with 11.0:1 compression and aggressively-domed pistons and have to use 100 octane to avoid detonation.

Be VERY careful that you do not put leaded high octane fuel in your engine.

Surprisingly, it does not increase the aggregate octane when mixed with lower octane unleaded, since it supposedly "strips" the octane of the unleaded fuel.

The catalytic converters are adversely affected by leaded fuel and, of course, there are severe penalties if you get found using leaded fuel in your street vehicle.

Some fuel additives may increase octane but generally in fractional amounts.

Still, it is your money and your vehicle, so your choice.

 

Octane is a measure of how fast the fuel will burn. Higher octane = slower burning.

Timing relates to at what point in the compression cycle the spark ignites the fuel.

If you've got a slower burning fuel you can ignite it sooner (ie more timing) so the peak explosive power can build more. Creates more power that way. Also since it's slower burning it will burn cooler and you can increase your a/f ratio before you worry about predetonation. Also more power.

However if you don't tune for the higher octane, you're doing yourself no good at all. Like already stated, you'll not be burning all your fuel so you can increase temps in your cat as the fuel burns there, gumming up your valves and piston head, o2 sensors, etc.

Moral of the story: Don't put in higher octane than recommended by the manufacturer unless you tune for it.

 

Umm, no.

http://en.wikipedia.org/wiki/Octane_rating

"The octane rating is a measure of the resistance of gasoline and other fuels to autoignition in spark-ignition internal combustion engines."

"It should be noted that octane rating does not relate to the energy content of the fuel (see heating value), nor the speed at which the flame initiated by the spark plug propagates across the cylinder."

 

again, i'll repeat...




nuff said.

 

I stand corrected.