93 vs. 87 Octane Chemical Difference

DaleM

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xblitzkriegx

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You do not need a lubricant with Toluene. Gasoline already has Toluene in it to begin with. Xylene will need a lubricant added with it if you use it constantly.

The main chemical difference between 87 and 91-93 is the amount of octane booster in it, in the form of Toluene, xylene, and/or ethanol.


30% mix of gas/Toluene or gas/xylene will give you 99/100 octane.

However, Toluene FAR more resistant to detonation in an engine compared to ethanol.
 

BOOGIE MAN

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I remember reading (maybe here a long long time ago, or possibly a magazine) that a half tank of 87 with a half of 93 worked out to like 91-92octane rating (depending on tank size) and not the 90 you would think it would be mathematically.

Again, not saying this is fact, just something I very vaguely remember reading
 

nxhappy

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be careful adding those chemicals. You can destroy the cats. You are better off using Torco.
 

RedVenom48

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Found out a gas station a few miles away carries 95 octane. A mix of VP100 and 91. For a little over $5 a gallon, ill just fill on that when the big boy blower is purchased. . Fill on 100 for track days
 

xblitzkriegx

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be careful adding those chemicals. You can destroy the cats. You are better off using Torco.

Neither Xylene nor Tolunene damages cats since both chemicals are already in gasoline in varying amounts to begin with. Adding more of either won't dmg cats either.
 

BigPoppa

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Most modern gasoline is just naphtha with alkylate added to increase octane. Since alkylate has low volatility, butane is added to bring Reid vapor pressure back up.

At least, that's how I program gasoline blending for many of my clients.

Now some places use reformate (xylene, toluene, etc.) from their cat cracker in addition to naphtha, but most of that is reserved for selling to the plastic industry.
 
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BigPoppa

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@BigPoppa Any poor man formulas to make race fuel, or do recommend just buying stuff from the professional manufacturers?
I would stick to buying it. With in-line analyzers used during blending, quality is pretty good these days.

Not to mention, trying to blend it yourself is a huge hassle and pretty dangerous. You would need something to mix the blend and that opens the real possibility of static buildup.

I recommend Sunoco race fuels. They may have gotten out of refining, but they still do blending and their quality is really good. They are also pretty much the only blender who still distributes real e85. If you get less than 85% ethanol at one of the stores selling their fuels, it was the delivery driver pumping the wrong fuel into the holding tanks.
 

DaleM

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