Here is an article on "Rocket fuel" for our cars.

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 $5/gal at chemical supply houses or paint stores.

Rocket fuel FAQ
Copyright 1999,2000 by Eliot Lim This paper may be freely distributed, provided it is distributed in its entirety
Last revised by Eliot Lim: February 8, 2000
Augmented and revised many times by Charles Smith: Most recently April 2006

. . . Background - by Eliot Lim

. . . Some basic questions about Toluene.

. . . Other questions people have asked.

. . . Questions about safety - is Toluene SAFE?

. . . What users have to say :-)

I get a lot of emailed questions about Toluene.

First, Toluene is Toluene - that is not a brand name. There is no other name.

Second, If you write and tell me all about your engine, and then just ask
how much Toluene you should use - I AM NOT EVEN GOING TO ANSWER.

   * You need to figure out what octane your engine needs.
   * Then you need to figure out the octane of gasoline you can purchase.
   * Then READ BELOW, use the formula below to figure out how much Toluene
      you need to add to whatever octane gas you can purchase so that you end up
      with the octane your engine needs.

Make sure the Toluene is well mixed with your gasoline.

Now - what you want to know:

Q: How much toluene should I use per tank of gas?

A: Octane ratings can be very easily calculated by simple averaging.

Toluene is 114 octane. So use this formula to figure what octane you get:

( Gallons_of_gas * Octane_of_gas ) + ( Gallons_of_toluene * 114 )
                        Total Gallons

This gives the octane of the mixture after you add toluene.

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:

    (14.6 * 92) + (1 * 114)  
  -----------------    =   93.4

The Audi A4 1.8T is a good example of a car that has very high octane needs if it has been modified to produce more turbo boost. The base compression ratio of this car is a very high 9.5:1 and when an additional 1 bar (14.7 psi) of turbo boost is applied on top of it, the resulting effective compression ratio is way beyond what 92 or 93 octane fuel can ever hope to cope with. Most modified 1.8Ts running without octane enhancement are running with severely retarded ignition timing and boost.

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.

A2: Experience of Charlie Smith in 2002. Sherwin Williams paint stores have it for $5.00 in a gallon can. They can order it in a 5 gallon can at $4.00 / gallon. They can order 55 gallon drums for about the same cost per gallon, but you have to have a dock unloading facility or a fork lift to get the drum(s) off of the delivery truck.

Q: But, where can I find it?

A: Toluene is a paint thing. You should be able to find it in the better auto-body supply stores and the better paint stores. It is a paint reducer - thinner - {I don't know what}. Here in the US I can find it at Sherwin Williams paint stores. Paint stores that sell to the auto repair shops should be able to get it.

I've had a lot of people say they can't find it. Try both paint supply shops and chemical supply houses. It should be easier to find than Moonshine Liquor ... and you certainly can find that :-)         So get creative folks, keep looking. And, if you had a difficult time finding it in your area, please drop me a note and tell me where you found it. I'll add that to this web page!

Q: Can I just dump in 100% toluene into the tank like the F1 racers?
          vroom vroom vroom

A: First of all, the F1 racers did not use 100% toluene, but 84%. The other 16% in their brew is n-heptane, which has an octane rating of zero. The reason for this strange combination is because the F1 rocket fuel was limited to the rules to being of 102 RON octane. The n-heptane is "filler" to make the fuel comply with the rules.

Because toluene is such an effective anti knock fuel it also means that it is more difficult to ignite at low temperatures. The Formula 1 cars that ran on 84% toluene needed to have hot radiator air diverted to heat its fuel tank to 70C to assist its vaporization. Thus too strong a concentration of toluene will lead to poor cold start and running characteristics. I recommend that the concentration of toluene used to not exceed what the engine is capable of utilizing. i.e. Experiment with small increases in concentration until you can no longer detect an improvement.

Q: Ok, what is the catch?

A: It should be mentioned that in the US, efforts are underway to reduce the aromatic content of gasolines in general as a higher aromatic content leads to higher benzene emissions. Benzene is an extremely toxic substance. However it should also be noted that the proportions that is being discussed in this FAQ is relatively small and in the grand scheme of things is probably insignificant. Moreover, the industrial standard for defining gasoline composition allows plenty of leeway in aromatic content and the proportions present in US gas is already lower than most other countries. I therefore feel that the information provided here is useful to a performance minded car enthusiast while not being significantly detrimental to the environment.


Here's a link to a Buick Regal turbo web site , that has their information about octane boosters. I have no idea if this site is correct, or how current it is. Some of the information looks very old.


Reference materials:

1. Gasoline FAQ

2. McLaren Honda Turbo - a technical appraisal
Ian Bamsey
ISBN 0-85429-840-1, published 1990

3. Chevron's excellent Motor Gasolines Technical Review

4. Agency for Toxic Substances FAQ on Toluene
    In summary:
    Use in a well ventilated area, don't drink even a little of it, and
    report spills of more than 1000 pounds to the National Response Center

5. Toxic Chemicals in your Environment (Australia) FAQ on Toluene
    In summary:
    this "Total Environment Center" likes a totally chemical free environment,
    and even at that they can't find fault about much more than acute exposure
    cases, and they also say not to drink any of it.

6. Exxon Chemical Americas - Toluene, Technical Material Safety Data Sheet

7. Recicladora Temarry de Mexico - Recycling Processor
    Recycling information and Material Safety Data Sheets on numerous chemicals including Toluene.    

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This information and pictures copyright Charles Smith, 2002.