I've been running 25% avgas (100LL) and 75% 93 as well as adding the startron treatment stuff with good results.

Thanks.I'll check it out. Bob

Toulene is 114-120 Octane do a google / Toulene and theres some cool info and the recipe is there ..good luck

Please also note that there are different octane ratings. Most common are the research number and the other is the motor number. Most pump ratings are the average of these two methods, (R+M)/2, while the aviation gas rating is the motor number. For this reason, 100LL is around 105 octane when compared with pump gas. Attached is a link that helps explain this.

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

I really dont want to turn down my boost

here in jersey we are 87, 89 and 92. there are some sunoco's that have the 94 ultra. there are still PLENTY OF CARS THAT REQUIRE 92 and if not used they pink and knock like mad under acceleration. cars i drive that call for 91 i usually run 2/3's of 92 and cap off with 89

That is saving you like a dollar on a 20 gallon tank??

So, if 92-93 goes away or becomes difficult to acquire, what the F do you do if you have 10:1 compression motors like the Ilmor 725 which requires 92 octane minimum...?

I'm not confident in the Toluene method.... since it's a solvent, seems it would dissolve rubber hoses etc.

I had done reseach for a couple of race cars. Here is all the info I have. Bare in mind this stuff is lethal. Wear protective mask and gloves. sorry for the large post.

Octane ratings can be very easily calculated by simple averaging. For example, the tank of an Audi A4 1.8TQ is 15.6 gallons. Filling it with 14.6 gallons of 92 octane and 1 gallon of toluene (114 octane) will yield a fuel mix of:

Final octane = ((gallons of gas * octane of gas) + (gallon of additive * octane of additive)) / (gallons of gas + gallons of additive)

(14.6 * 92) + (1 * 114) / 15.6 = 93.4

Q: How much does toluene cost, and where can I buy some?

A: $10/gallon in a one gallon can at a hardware store, about $6/gallon in a 5 gallon can from a chemical supply or paint store, or $3/gallon in a 55 gallon drum from a chemical supply warehouse.

Well, this is the case for Toluene and what it can do for your V8Q if you been using anything less than 92+ octane. Get some.Try it. No harm, no risk. Use about 24-32 ounces per 1/2 to full tank. You will not look debonair. You will have to suspend your "cool" look. You may want to try this alone. YOU WILL HAVE THE ****TEST, MOST PLASTER, GRIN ON YOUR FACE YOU HAVE EVER HAD! It won't come off. You'll tell the kids, daddy has his own "transformer". It will be like a new car...no, better than new!

(**note: this person confused RON octane mentioned in the owners manual with R+M/2 octane that is sold in the pump. 95-99 RON is roughly equivalent to 91-94 R+M/2)

Richard Lassiter's "How to Mix Your Own Brew"
FORMULA 1
Toulene
R+M/2...114
Cost...$2.50/gal
Mixtures with 92 Octane Premium
10%...94.2 Octane
20%...96.4 Octane
30%...98.6 Octane
Notes: Common ingredient in Octane Boosters in a can. 12-16 ounces will only raise octane 2-3 *points*, I.e. from 92 to 92.3. Often costs $3-5 for 12-16 ounces, when it can be purchased for less than $3/gal at chemical supply houses or paint stores.

FORMULA 2
Xylene
R+M/2...117
Cost...$2.75/gal
Mixtures with 92 Octane Premium
10%...94.5 Octane
20%...97.0 Octane
30%...99.5 Octane
Notes: Similar to Toulene. 12-16 ounces will only raise octane 2-3 *points*, I.e. from 92 to 92.3. Usually mixed with Toulene and advertised as *race formula*.

FORMULA 3
Methyl-tertiary-butyl-ether (MTBE)
R+M/2...118
Cost...$3.50/gal
Mixtures with 92 Octane Premium
10%...94.6 Octane
20%...97.2 Octane
30%...99.8 Octane
Notes: Oxygenate. Very common in octane booster products. Has lower BTU content than toulene or xylene, but oxygenate effect makes the gasoline burn better and produce more energy.

FORMULA 4
Methanol or Ethanol
R+M/2...101
Cost...$0.60 - $1.75/gal
Mixtures with 92 Octane Premium
10%...94.3 Octane (Methanol)
10%...94.7 Octane (Ethanol)
20%...Not Recommended
Notes: Methanol is wood alcohol. Ethanol is grain alcohol and found in Gasohol in 10% ratios. Both alcohols are mildly corrosive and will eat gas tank linings, rubber and aluminum if used in excessive ratios. Main ingredient in "Gas Dryers", combines with water.

FORMULA 5
Isopropyl Alcohol and Tertiary Butyl Alcohol
R+M/2...101
Cost...$0.60-$1.50/gal
Mixtures with 92 Octane Premium
10%...94.5 Octane
20%...Not Recommended
30%...Not Recommended
Notes: Similar to Methanol/Ethanol. Isopropyl Alcohol is simply rubbing alcohol.


MAKE YOUR OWN OCTANE BOOST
How to make your own octane booster (this is the basic formula of one of the popular octane booster products). To make eight 16 ounce bottles (128 oz = 1 gal):

100 oz of toulene for octane boost
25 oz of mineral spirits (cleaning agent)
3 oz of transmission fluid (lubricating agent)

This product is advertised as "octane booster with cleaning agent *and* lubricating agent!". Diesel fuel or kerosene can be substituted for mineral spirits and light turbine oil can be substituted for transmission fluid. Color can be added with petroleum dyes.

Its in our gas already BIG DAddy and more in AV gas , The nascar car guys are'nt having a problem and some run as much as 80% Toulene ......