Octane boost

[eightsandaces]

I occasionally like to run octane boost, it seems to make the car smoother. I have used 104+ and the stuff made from jet fuel, both work well. A recent trip to the dollar store and I found what looks to be toluene booster, is this stuff safe to use?

[Lobo1186]

yes it is safe... at least as far as I have ever read. however i do believe since it lacks detergents that it can cause more soot buildup in the motor. but for once and a while basis it shouldnt be harmful.

HERE IS AN OCTANE MIX CALCULATOR

if you use xylene or toluene (i forget the octane rating of those) just use the calculator. personally I would rather use race fuel found at any race track. much simpler and I think cheaper.

[Cloudsurfer]

Originally Posted by eightsandaces

I occasionally like to run octane boost, it seems to make the car smoother. I have used 104+ and the stuff made from jet fuel, both work well. A recent trip to the dollar store and I found what looks to be toluene booster, is this stuff safe to use?

Hate to burst your bubble on this, but Jet-A is basically kerosene, and has absolutely no place anywhere near a piston engine. Furthermore, if you actually look at independent tests, the most you will ever gain by either adding toluene (up to about 20% by volume) or pretty much any of the variety of store bought octane boosters (used at their maximum concentration), is about 2 octane points. However, since these methods work by raising octane at the expense of combustion quality (they create a slower burning fuel), you'll actually make less power, especially on a high revving engine, and in some cases, the fuel burns so slowly that it will still be burning as it exits the exhaust valve, which is a great way to destroy O2 sensors and cats.

There's a huge difference between high quality (racing fuels, leaded AvGas (for piston aircraft), high octane gasoline, and "modified" street fuels. Start pricing out cans of "Jet Fuel Octane Booster" or toluene (per gallon, at a high enough concentration to make a difference) and you'll quickly find it's cheaper to just run 100 unleaded race fuel if you have a car that needs it (which if you have a remotely stock Boxster, you don't).

What I'm anxiously waiting for, is the aviation world to switch over to a 100 octane unleaded fuel (and AvGas is rated on the MON scale, which is conservative compared to the R+M/2 scale used in the auto world in the US, so the 100UL AvGas will actually be around 104 octane R+M/2.

[eightsandaces]

Cloud,

That's why I asked, I only used it occasionally, as far as "bursting bubbles" if the 104+ didn't make a perceptible difference do you think I'd still buy it? Whether it's bad for the engine is an entirely different subject. I'll start looking for 100 or competition car gas. I've only seen it in a few places, best one can do near me is Sunoco 93.

[JTP]

Originally Posted by eightsandaces

Cloud,

I'll start looking for 100 or competition car gas. I've only seen it in a few places, best one can do near me is Sunoco 93.

Delta Sonic sells race gas (I think 103 octane) in upstate NY. Here's where they're available:

New York:
Ridge & Langner Rd., West Seneca
2285 Walden Ave., Cheektowaga
2590 Delaware Ave., Buffalo
Niagara Falls Blvd.& 80th St., Niagara Falls
4983 Transit Rd., Williamsville
990 West Ridge Rd., Greece
2970 West Henrietta Rd., Henrietta

Illinois:
159th & Oak Park Dr., Tinley Park
1415 Ogden Ave., Downers Grove

[Cloudsurfer]

Originally Posted by JTP

Delta Sonic sells race gas (I think 103 octane) in upstate NY. Here's where they're available:

New York:
Ridge & Langner Rd., West Seneca
2285 Walden Ave., Cheektowaga
2590 Delaware Ave., Buffalo
Niagara Falls Blvd.& 80th St., Niagara Falls
4983 Transit Rd., Williamsville
990 West Ridge Rd., Greece
2970 West Henrietta Rd., Henrietta

Illinois:
159th & Oak Park Dr., Tinley Park
1415 Ogden Ave., Downers Grove

Most Delta Sonic's that I've been to have straight 100 Octane unleaded. Great stuff.

[Lobo1186]

if you cannot get race fuel you can go just to home depot and buy xylene or tuolene. if you google it you will get a plethora of info and you can use the above supplied calculator to mix your own!

[Cloudsurfer]

Originally Posted by Lobo1186

if you cannot get race fuel you can go just to home depot and buy xylene or tuolene. if you google it you will get a plethora of info and you can use the above supplied calculator to mix your own!

Glad someone read what I posted previously. [SARCASM]

[986FortyEight]

There has been some serious threads on the subject in the past on this board and others, and it seems that unless you reprogram your DME to use maps built with high octane gas into consideration, there is no particular performance related advantage to running higher octane gas in your stock boxster.
But if it makes you happy...

[Lil bastard]

Noticeable difference = Placebo Effect!

These additives raise the octane rating only a few tenths of a point.

To get any real gains, you need 10-20% by volume which equals 1-2 gallons of the stuff on a Boxster, and then, you'd only see a mild effect on performance.

On the other hand, these things are powerful solvents and will reek havoc with your engine oil's additive pkg. necessitating more frequent, expensive, oil changes.

Long term they will negatively effect the fuel system components - fuel lines, connectors, plastic sending units, etc.

Save your money... they're not really worth it.

Cheers!

[Lobo1186]

Originally Posted by Cloudsurfer

Glad someone read what I posted previously. [SARCASM]

I read what you said. I just ignored it. the question at hand was is it safe... and it is. toluene first of all is already present in gasoline as an octane booster.

"Q: Will toluene damage my engine or other parts of my car?

A: A 5 or 10% increase in the aromatic content of gas will most likely be well within the refining specifications of gasoline defined by ASTM D4814, which specify an aromatic content of between 20% and 45%. What this means is that if the 92 octane gas that you started off with had an aromatic content of say 30% and you increased it by 10% to 40% you would still be left with a mix that meets the industry definition of gasoline. So the above question would amount to: "Will gasoline damage my engine or other parts of my car?"

Even in the unlikely event that the 92 octane gas has a aromatic content of 45% the resulting mix would still be within the bounds of gasoline sold in other countries. "

"Toluene is a pure hydrocarbon (C7H8). i.e. it contains only hydrogen and carbon atoms. It belongs to a particular category of hydrocarbons called aromatic hydrocarbons. Complete combustion of toluene yields CO2 and H2O. This fact ensures that the entire emission control system such as the catalyst and oxygen sensor of your car is unaffected. There are no metallic compounds (lead, magnesium etc), no nitro compounds and no oxygen atoms in toluene. It is made up of exactly the same ingredients as ordinary gasoline. In fact it is one of the main ingredients of gasoline.

Toluene has a RON octane rating of 121 and a MON rating of 107, leading to a (R+M)/2 rating of 114. (R+M)/2 is how ordinary fuels are rated in the US. Note that toluene has a sensitivity rating of 121-107=14. This compares favorably with alcohols which have sensitivities in the 20-30 range. The more sensitive a fuel is the more its performance degrades under load. Toluene's low sensitivity means that it is an excellent fuel for a heavily loaded engine.

Toluene is denser than ordinary gasoline (0.87 g/mL vs. 0.72-0.74) and contains more energy per unit volume. Thus combustion of toluene leads to more energy being liberated and thus more power generated. This is in contrast to oxygenated octane boosters like ethanol or MTBE which contain less energy per unit volume compared to gasoline. The higher heating value of toluene also means that the exhaust gases contain more kinetic energy, which in turn means that there is more energy to drive turbocharger vanes. In practical terms this is experienced as a faster onset of turbo boost. "



SO as you can see this is a nice little article I have found that is in line with every other piece of info I have found on this subject. here is the link and read for yourself.

the article (not mine)

[Lobo1186]

is it true that the advantage for higher octane fuel on a NA car are minimal?... yes, but not non existent, and if he wants to have whatever advantage he can get who are we to judge?

[Cloudsurfer]

Originally Posted by Lil bastard

Noticeable difference = Placebo Effect!

These additives raise the octane rating only a few tenths of a point.

To get any real gains, you need 10-20% by volume which equals 1-2 gallons of the stuff on a Boxster, and then, you'd only see a mild effect on performance.

On the other hand, these things are powerful solvents and will reek havoc with your engine oil's additive pkg. necessitating more frequent, expensive, oil changes.

Long term they will negatively effect the fuel system components - fuel lines, connectors, plastic sending units, etc.

Save your money... they're not really worth it.

Cheers!

Glad to know we're on the same page with this

To continue the "is it safe" discussion, consider that at 20% concentration (enough to actually make a difference, toluene or xylene, as solvents, offer zero lubrication, and significantly degrade the lubricity of the remaining gasoline. This has obviously negative effects on things like fuel pumps, but is also particularly bad for the upper cylinder area, which relies partly on the fuel to lubricate the rings, and the rest on oil. They will also eat away at the fuel system. Adding a strong solvent to the mix washes the oil film from the cylinder walls, and you will experience increased cylinder bore and ring wear. Whatever small amount that makes it past the rings will degrade the oil, and cause increased bearing wear, also necessitating more frequent oil changes to try to combat this effect (added cost).

Both of these chemicals are also incredibly toxic to handle, and dispose of their containers.

Some will point out that, yes, Formula 1 cars used to run almost straight toluene, and that's true. Their motors also only had to last one race, and it was human health concerns that caused F1 to ban the fuel.

Lobo, I'm not sure where you're getting your information, but substituting solvent for fuel on a street car that doesn't get its engine rebuilt every few races is not a good idea, nor is handling this stuff on a regular basis.

To put this into practicality, last time I saw toluene at Home Depot, it was about $10/ gallon. Substituting 20% toluene (at $10/gal) with 80% premium unleaded (call it $3/gal) yields an overall fuel cost of $4.40/ gal. You can buy 100 octane race fuel for that price, and that is a high quality, safe fuel (both for your health and the health of your motor).

[Lobo1186]

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.


Rocket fuel FAQ
Copyright ã 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
Last augmented by Charles Smith: January 6, 2003


Background

In late 1997 I became the lucky owner of 1 out of 150 1998 Porsche 993 Targas, the very last of the air cooled classics. As I drove it through the winter of 1997 and into the spring of 1998 I noticed that the engine lost some of its sweetness. Since this behavior was strongly related to ambient and engine temperature I suspected that the engine electronics were retarding its ignition timing due to insufficient fuel octane.

I started experimenting with octane boosting by first adding small doses of over the counter octane boosters and noticed immediate improvement. The engine ran smoother and quieter, was more willing to rev and had noticeably sharper throttle response. The octane shortage was confirmed by the sticker on the filler cap that stated that 93 octane fuel was needed. Since the highest octane rated fuel that was commonly available in Washington state is 92, I decided to investigate long term cost effective octane boosting so that I could fully enjoy the performance that this car offered.

My other car at the time, a 1990 Audi V8 quattro had an even more dramatic response to octane boosting. I managed to convince a few good friends to try it and the reaction was overwhelmingly positive. When I attempted a broader based dissemination of this exciting find, I was greeted largely by broad unyielding skepticism and plenty of FUD (fear, uncertainty, doubt) regarding toxicity, safety and engine damage. There arose a need to more clearly explain the details of octane boosting, hence giving rise to this article.


Q: Will my car benefit from octane boosting?

A: Consumer organizations have effectively emphasized the larger markups that oil companies charge for high octane gasoline, implying that for most vehicles higher octane fuel is a complete waste of money. It has been quite a long time since the consumer alert was issued. Since then engine technology has evolved greatly, while people's perceptions generally have not.

Modern vehicles now use computerized engine management systems that can react to engine knock and retard ignition timing if low octane fuel is being used. Consequently cars are now being manufactured with very high compression ratios that appear to give good fuel economy and at the same time good performance. This combination does assume that fuel of adequate octane is being used.


Q: Why bother to boost octane at all since my engine can run just fine on lower octane fuel?

A: For a high compression engine to run on low octane fuel, the engine management system will need to retard the ignition timing to prevent preignition or pinging. Retarding the ignition timing means that the firing of the spark plug is delayed until a later moment in the compression stroke. It does not take much to see that a later onset of combustion means that the combustion is less complete, which in turn mean less power and poorer fuel economy. It is possible that the casual driver will still come out ahead in terms of saving money by using low octane fuel, but the retarded ignition advance also means a rougher running engine and a much duller throttle response. Thus octane boosting is not necessarily of interest to all motorists but rather the enthusiasts.

For turbocharged or supercharged engines, insufficient octane will also lead the engine management system to curtail the amount of boost which in turn defeats the purpose of these engines.


Q: How did you discover using toluene?

A: Someone came across a web page that described various DIY home brew octane booster formulas. One of which used toluene as its main ingredient. As a Formula 1 racing fan of many years, I recalled that toluene was used extensively in the turbo era in the 1980s by all the Formula 1 teams. The 1.5 liter turbocharged engines ran as much as 5 bars of boost (73 psi) in qualifying and 4 bars (59 psi) in the actual race. Power output exceeded 1500bhp, which translates into 1000bhp/liter, an astronomical figure.

A motorsports journalist, Ian Bamsey, was able to obtain Honda's cooperation for his book "McLaren Honda Turbo, a Technical Appraisal". The book documents the key role that the toluene fuel played in allowing these tiny engines to run so much turbo boost without detonation. The term "rocket fuel" originated from the Formula 1 fraternity as an affectionate nickname to describe its devastating potency. Thus I concluded that I should focus my research on using toluene for my octane boosting project.

Individuals with good long term memory will recall that when unleaded gasoline was first introduced, only low octane grades were available. While it is not entirely clear that high octane super unleaded gas came about as a result of the advances in fuel technology in Formula 1, there is every reason to suspect that this is indeed the case, since many of the major oil companies were involved in the escalating race to develop increasingly potent racing fuel during this era.


Q: Why do you think toluene is better than other types of octane boosters?

A: Several reasons:

Mindful of the evil reputation of octane boosters in general, toluene is a very safe choice because it is one of the main octane boosters used by oil companies in producing ordinary gasoline of all grades. Thus if toluene is indeed harmful to your engine as feared, your engine would have disintegrated long, long ago since ordinary pump gasoline can contain as much as 50% aromatic hydrocarbons.

Toluene is a pure hydrocarbon (C7H8). i.e. it contains only hydrogen and carbon atoms. It belongs to a particular category of hydrocarbons called aromatic hydrocarbons. Complete combustion of toluene yields CO2 and H2O. This fact ensures that the entire emission control system such as the catalyst and oxygen sensor of your car is unaffected. There are no metallic compounds (lead, magnesium etc), no nitro compounds and no oxygen atoms in toluene. It is made up of exactly the same ingredients as ordinary gasoline. In fact it is one of the main ingredients of gasoline.

Toluene has a RON octane rating of 121 and a MON rating of 107, leading to a (R+M)/2 rating of 114. (R+M)/2 is how ordinary fuels are rated in the US. Note that toluene has a sensitivity rating of 121-107=14. This compares favorably with alcohols which have sensitivities in the 20-30 range. The more sensitive a fuel is the more its performance degrades under load. Toluene's low sensitivity means that it is an excellent fuel for a heavily loaded engine.

Toluene is denser than ordinary gasoline (0.87 g/mL vs. 0.72-0.74) and contains more energy per unit volume. Thus combustion of toluene leads to more energy being liberated and thus more power generated. This is in contrast to oxygenated octane boosters like ethanol or MTBE which contain less energy per unit volume compared to gasoline. The higher heating value of toluene also means that the exhaust gases contain more kinetic energy, which in turn means that there is more energy to drive turbocharger vanes. In practical terms this is experienced as a faster onset of turbo boost.

Chevron's published composition of 100 octane aviation fuel shows that toluene comprises up to 14% alone and is the predominant aromatic hydrocarbon. Unfortunately composition specifications for automotive gasoline is harder to pin down due to constantly changing requirements.

Chevron's web site also describes the problems of ethanol being used in gasoline.

MTBE was heavily touted as a clean additive several years ago, and became a key ingredient in reformulated gasoline that is sold in California. But recently new studies arose that showed that MTBE was far more toxic than previously imagined. Organizations such as oxybusters have formed around the country to eliminate the use of MTBE in gasoline and several states, including California have passed new laws to eventually outlaw MTBE.


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

A: 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:

(14.6 * 92) + (1 * 114) / 15.6 = 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: Will toluene damage my engine or other parts of my car?

A: A 5 or 10% increase in the aromatic content of gas will most likely be well within the refining specifications of gasoline defined by ASTM D4814, which specify an aromatic content of between 20% and 45%. What this means is that if the 92 octane gas that you started off with had an aromatic content of say 30% and you increased it by 10% to 40% you would still be left with a mix that meets the industry definition of gasoline. So the above question would amount to: "Will gasoline damage my engine or other parts of my car?"

Even in the unlikely event that the 92 octane gas has a aromatic content of 45% the resulting mix would still be within the bounds of gasoline sold in other countries.


Q: Isn't toluene an extremely toxic substance?

A: The common perception of toluene's toxicity far exceeds reality. Fortunately there is an ample body of information available that specifically addresses this question. Toluene is more toxic than gasoline but it is certainly not agent orange or cyanide. See the Agency for Toxic Substances link below in the reference section.

US Environmental Protection Agency Chemical Summary

US Agency for Toxic Substances and Disease Registry (ATSDR)

National priority list of toxic substances
Note that the ATSDR also rates gasoline as a hazardous substance.

Mobil's spec sheet for toluene even goes as far as saying that "Based on available toxicological information, it has been determined that this product poses no significant health risk when used and handled properly."


Q: Isn't toluene an active ingredient of TNT (trinitrotoluene) and is thus deadly?

A: In the same way that cotton wool is the base ingredient of nitrocellulose (guncotton) which in turn is the main ingredient in modern smokeless gunpowder. Using this reasoning one could conclude that cotton wool is a deadly substance. This question reflects a poor understanding of basic chemistry but unfortunately it has been asked often enough.


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 to get the drum(s) off of the delivery truck.


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.

[Lobo1186]

Q: Why not simply use racing gasoline or aviation fuel?

A1: Most types of aviation fuel have very high lead content, which would rule out cars equipped with catalytic converters. Most piston engined aircraft burn leaded fuel. Also aviation fuel has a very different hydrocarbon mix to optimize volatility properties at high altitude.

A2: Racing gasoline could be a much more convenient way to run high octane fuel compared to having to constantly mix in toluene with each fill up. There are, however a few caveats:


You don't know for sure if you are really getting what is being advertised. You should find out if the fuel inspectors verify the actual octane of the racing gasoline in addition to ordinary gasoline. If you paid $3/gallon and only got 94 or 95 octane instead of 100 octane you may conclude erroneously that your car does not benefit from octane boosting.

You don't know what octane boosters are used in the racing gasoline. The worst case scenario is buying leaded racing gasoline without knowing it. Unleaded racing gasoline may still contain damaging octane boosters like MMT or methanol. A very high alcohol content will lead to fuel line erosion, accelerated fuel pump wear, very poor fuel economy and possibly lower performance, as alcohols have a less impressive MON rating than aromatics.

It takes smaller quantities of toluene to achieve the same octane boost compared to 100 octane racing gas. I have not seen unleaded racing gas for sale that exceeds the octane rating of toluene.

Since toluene is not officially sold as a fuel, gas taxes do not apply. Also racing gasoline tend to have higher markups being of interest to the performance minded enthusiast and thus is very likely to be more expensive to buy and use long term than toluene, which is typically used in more mundane applications like paint thinner.

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.

--------------------------------------------------------------------------------

Since I didn't have any reference point for how much to use, I dumped about a half gallon of this mix into a mostly empty tank (the GT has a 16 gallon tank) and then filled up with Chevron 92 octane.
I didn't get to drive the car until PIR the next morning, (my GF doesn't like the 200; it's too big) but the report was that there was no change for a mile or so, and then all of a sudden, the engine seemed to smooth out and became quite eager to rev and run.
Well, by that calculation, I only managed to bump the octane to just shy of 93, but it seemed to make a big difference. I ran the car hard all day, (for reference, it's got an '87 MC turbo motor, K26, 12psi boost, and currently no intercooler) and even at 12 pounds of boost, I never once felt the ECU backing the timing off. Granted, the ambient temps never got above 50, and my water and oil temps were rock solid. (Oil just pushing above 100C)

The only cars that I had to get out of the way for was an Integra Type R and a couple of race-prepped P-cars. I even managed to lap the NSX once! It was a really good day!

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.

For some reason the link will not work so I bring it to you. read it if you want if not skip over it.

[eightsandaces]

Originally Posted by Lobo1186

is it true that the advantage for higher octane fuel on a NA car are minimal?... yes, but not non existent, and if he wants to have whatever advantage he can get who are we to judge?

Didn't mean to get anyone upset, actually it used to have the effect of making the car run smoother, that's the only way I can explain it, it even shifted smoother. Putting the under-pulley on has made the car better in so many ways that I don't really care about the booster, I just happen to see it for a buck, which seemed too good to be true given the cost of 104+. Thanks for all the gas info, really incredibly complex, you guys know some stuff...

[Lobo1186]

Originally Posted by Cloudsurfer

Glad to know we're on the same page with this

To continue the "is it safe" discussion, consider that at 20% concentration (enough to actually make a difference, toluene or xylene, as solvents, offer zero lubrication, and significantly degrade the lubricity of the remaining gasoline. This has obviously negative effects on things like fuel pumps, but is also particularly bad for the upper cylinder area, which relies partly on the fuel to lubricate the rings, and the rest on oil. They will also eat away at the fuel system. Adding a strong solvent to the mix washes the oil film from the cylinder walls, and you will experience increased cylinder bore and ring wear. Whatever small amount that makes it past the rings will degrade the oil, and cause increased bearing wear, also necessitating more frequent oil changes to try to combat this effect (added cost).

Both of these chemicals are also incredibly toxic to handle, and dispose of their containers.

Some will point out that, yes, Formula 1 cars used to run almost straight toluene, and that's true. Their motors also only had to last one race, and it was human health concerns that caused F1 to ban the fuel.

Lobo, I'm not sure where you're getting your information, but substituting solvent for fuel on a street car that doesn't get its engine rebuilt every few races is not a good idea, nor is handling this stuff on a regular basis.

To put this into practicality, last time I saw toluene at Home Depot, it was about $10/ gallon. Substituting 20% toluene (at $10/gal) with 80% premium unleaded (call it $3/gal) yields an overall fuel cost of $4.40/ gal. You can buy 100 octane race fuel for that price, and that is a high quality, safe fuel (both for your health and the health of your motor).

seeing is it is already a commercial fuel additive at the pump it can be used within limits. ive read that it is somewhere around 45% is within limits in the US to be classified as gasoline.

as far as health concerns... life is dangerous ive never let it stop me from living it.

[eightsandaces]

Haha on toxic to handle, look at a lot of hair products, I've seen tolunene in many.

[Lil bastard]

Toluene is particularly toxic to the respiratory system.

Toluene was used in F1, but only so the timing could be advanced radically on a motor with Forced induction - these were 1.5 Ltr. Turbocharged motors running in excess of 20PSI boost pressures to produce upwards of 700BHP.

The Boxster motor is hardly that, and the timing is essentially non-adjustable (outside of developing and programming new timing/fuel maps into the DME). So you wouldn't be able to take advantage of it all anyway.

Toluene, while approved by the EPA as a fuel additive, was only approved in an attempt to eliminate MBTE, a much bigger offender.

Just because F1 used it means nothing to a street engine.

In the '70's, BMW used to season it's F1 engine blocks by throwing them into snow banks in winter and pissing on them - that's right, the engineers used to go outside and pee in the blocks! Urine contains significant amounts of Nitrogen and this nitrification technique caused nitrogen to bond with the surface of the blocks making them stronger.

Are you advocating that we do this too???

Cheers!

[Lobo1186]

ive used toluene and xylene as a solvent for cleaning many times. its not a big deal. with anything else take care and its fine.

you two perpetuate this F1 argument. I have never once said that f1 uses it (regardless of the fact that they do or did, personally i dont drive an f1 car so it makes that logic faulty) . in fact all I have said is that it is currently used in the fuel you buy at any gas station already. all you would be doing is adding more which up to around 40 - 45% still constitutes gasoline in the US.

by all means don't put any more in your gas, that is your prerogative.