STP Octane Boosters and Fuel System Cleaners - The Unofficial BMW M5 Messageboard (m5board.com)

apk1013 · 12th October 2004, 16:45

I ran my car with these two products from STP, and it really ran amazing. The throttle response was amazing, and the car was flying. I would really recommend these two products if you need them to put someone in their place.

Have any of you guys had similar experiences with these types of products?

Andrew

SC'dKellenersM5 · 12th October 2004, 17:22

I think a high enough concentrate of those additives will always make a difference. I have used 2 bottles of the STP fuel system cleaner in my m3 as well as NOS Racing formula and 108 ocatane booster (the BIG bottle). I have done the same with the m5 and things are very very very different with those additions to the fuel system.

It is just like adding 100 octane fuel...but for less. The large bottle of 108 octane is something like $10.00 and it treats the whole tank.

marinakorp · 12th October 2004, 21:47

similar results can be had using toluline... what some of the octane boosters use

I usually clean the Fuel Injectors using the Techron ... I usually stay away from the octane boosters... the car is not set to run any better on above 93 anyway.. so the additional octane is not going to affect the performance greatly (IMHO).

XrayMD · 13th October 2004, 04:19

I agree with the Techron fuel system cleaner recommendation. I felt a difference after a tank of it. As far as octane boosters go, generally they are a waste of money as you might go from 93.0 octane to only 93.1 octane at best.

speedmonkee · 13th October 2004, 20:07

For those of us who can only get 91 octane as the highest gas grade at the pump (CA & other western/midwest states), Tolulene will work to get you to 93 octane a lot cheaper than these other branded additives. Turbo'd cars (like the WRX) run a lot better on higher octane, but with our M5, 93/94 octane is probably the limit.

FYI: A 5 gallon can of tolulene costs under $30 at a local shop here in CA. (Of course its probably going to rise with the recent oil prices).

here's an interesting paste on this stuff:

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 ******ed 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.

Quote:

Originally Posted by XrayMD

I agree with the Techron fuel system cleaner recommendation. I felt a difference after a tank of it. As far as octane boosters go, generally they are a waste of money as you might go from 93.0 octane to only 93.1 octane at best.

XrayMD · 13th October 2004, 20:11

Yes, I agree with the toluene for increased octane. WHat I was referring to is the stuff that's sold at Wal-Mart and auto stores that is in a much smaller container than one gallon.

speedmonkee · 13th October 2004, 20:44

Agreed. Apologize for the confusion - just trying to add to the thread in general - not trying to reply directly to your quote - sorry - still getting used to these threads on this board.

Jeremy

Quote:

Originally Posted by XrayMD

Yes, I agree with the toluene for increased octane. WHat I was referring to is the stuff that's sold at Wal-Mart and auto stores that is in a much smaller container than one gallon.

apk1013 · 14th October 2004, 16:40

I put STP's new octance booster in the car, and the results have completely shocked me. The car is running amazing. The throttle response is better, and acceleration is definitely better. Please give it a try. Put it in on an empty tank and then fill up. The most amazing thing is that I am getting about 50 more miles to each tank! My computer said I had 310 miles to empty when I filled up, and I got 240 out of it under very aggressive driving conditions and racing. I am telling you that you have to try this stuff.

Andrew
Is there any negative consequence of using octane booster??