safe to run 90 ethanol free ?

Ethanol, 113 octane rating, premium gas tops out at 93. There is not quite the heat energy in it as premium that's why ethanol powered race stuff is over fueled. Regular gas for me I hate to waste money, last two Tacoma's both had 300+ K.

 

Ethanol has higher octane rating (110ish) so it actually can help a tuned engine make more power. Alcohol drag engines can make 11,000 hp (!) which is pretty good. Of course, the engines are rebuilt pretty regularly ;-)
Tailpipe emissions are also lower with Ethanol mixes. In most of New England you can't even buy ethanol free fuel unless it is for an off-road vehicle, airplane or snowmobile. Small 1 gallon cans of pure gas are sold in hardware stores for small engines (weed eaters, chain saws, etc).

 

Was tuning e85 on my turbo dsms almost 20 years ago. I now run it in my CTS-V. Oil and water temps stay 10* cooler. Can run 5* additional timing and never a blip of detonation or timing pull. Paying $2.50/g when premium is $5/g.

 

Thats not how octane works. Octane is just resistance to burn - its' not power, its not energy - its simply resistance to burn. Drag racers run astronomical compression ratio's so they need a super high octane (higher resistance to burn) to prevent fuel pre-detonation. 110 octane is not more powerful than 87 octane.

Ethanol is an awesome octane boost because it's really hard to burn, but it also separates from fuel, encourages condensation and water also increases octane. A lot of gas station E0 is just normal gas that has been allowed to separate. You can buy kits for cheap to separate ethanol in your own gas for your own small engines.

Now, modern engines are designed to run on ethanol where older motors and most motorcycles are not. Ethanol destroys anything rubber, like fuel system gaskets, fuel lines etc. So, do not run Ethanol in an older vehicle if you can help it. But, depending on several variables, most will see an increase in mileage by running E0.

Now, is "premium" better/worse than regular (regardless of Octane) that's an entirely different discussion because some stations, its almost identical and other stations, they have vastly different additives. One thing I read claimed that all the additives in Chevron premium are so bad that you should never never run Chevron premium because it just increases deposits on the valves. But, thats another discussion altogether.

 

Basically the higher the octane fuel the more btu's it makes.

 

Yeah, I know, I'm down with most of the laws of Thermodynamics ;-)

That is why I never said "Ethanol has more BTUs than gasoline" ;-)

What I said was " Ethanol can help a tuned engine make more power "

 

Octane has nothing to do with the number of btu's. It's entirely the resistance to detonation.

https://www.sunocoracefuels.com/tech-article/octane-stability-high-octane-vs-low-octane-fuels

 

Not fully. Mandatory evacuation really just means you cannot return if you leave.

Fair amount of hotel and "essential workers" coming and going since the hotels were housing some evacuees from the edges of town. LE and DOT checkpoints set up checking for work IDs or IDs to show you live there to prevent looting.

I was up there as part of the fire response and it was pretty empty in the streets. Would have been a good time to film some B roll footage for EOTWAWKI movies.

 

I've been using nothing but Shell 91 E0, since I bought it; 6 years/33,000 miles.

E0 has way more aromatics to achieve the octane rating.
Separating 87 & 89 E10 would give you 84 E0; separating 91 & 93 E10 would give you 88 E0.