195 premium fuel

[Tyguy]

Also, for those seeking non-ethanol gas....doesn't ethanol increase octane?

Yep. Pure ethanol is 113 octane rating, so if you take a given base stock gasoline and add ethanol, octane rating will go up. But, refiners already know this so the final octane rating advertised takes into account the octane boost from ethanol.

 

[FSH 210 Sport]

There are several problems with ethanol...

One, ethanol has roughly 44,000 btu’s per gallon to gasoline’s 95,000 btu’s per gallon. So a 10% mix of ethanol takes away from the energy potential of your fuel.. (only a govt could require oxygenation via ethanol and then require higher mpg)

Two, ethanol bonds instantly with water. So now you have the very real potential of water in your fuel along with the ethanol. When this ethanol reaches saturation, the water ethanol mix can fall out of suspension aka phase separation. This creates a sludge that is way no good. When the water falls out of suspension while in your fuel system while parked, this leads to corrosion of all components within the fuel system, clogs injectors, and in my case caused the seizure of a fuel pressure regulator on my FI dirt bike.

There are several products on the market to prevent phase separation, the product I was using is Star Tron. I never had another problem again once I used this product. I have left ethanol laced fuel in my FI dirt bikes for the better part of a year that was treated with Star Tron and the bikes start right up with no issues.

Now that I live where non ethanol fuel is readily available I use only that, and I mix 85 & 91 at the proper ratio to get the 88 octane that is required for my boat. Octane Mixture Calculator

 

[tdonoughue]

I am actually surprised at this. Not doubtful, but surprised. I was always told that octane rating was how slowly a fuel burned, not how quickly. In other words, the reason high octane fuel is desirable is because it burns more slowly (and therefore more completely). It prevents knocking, etc. by eliminating precombusion.

So ethanol is higher octane. Which means it burns more slowly. But I do know that it burns more completely (which is why the environmentalists recommend it--incomplete burn causes all sorts of issues with emissions) and gives more immediate power (though not overall power). I would have thought it therefore lower octane (and more prone to knocking, preignition, etc.). But that is not the case.

You learn something new every day.