[Guest84]

Anyone tried these? I tried them on motorcycles in another life...not sure if I want to experiment with my passenger vehicles Anyway, after reading Hacks thread on his 100 octane fuel, just curious if anyones had any experiences with Octane boosters.

 

[in_d_haus]

Most are just plain bad for your car! If you want to pump up your octane you can add some racing fuel to your tank occasionally. Tolulene will also raise the octane but I can't remember the proportion. DON'T use a product like "104 Octane Boost" it will kill your injectors!

 

[Guest84]

Thanks Haus! I've always assumed that products that seem to be "too good to be true" usually are!

 

[Alex Baumann]

Thanks Haus! I've always assumed that products that seem to be "too good to be true" usually are!

Rip, since you're at Boeing, how bout filling some Av-gas ?

 

[Guest84]

Rip, since you're at Boeing, how bout filling some Av-gas ?

"At Boeing"...well, no fuel pumps here at my office building! In-d-haus OTOH might have access since hes a private pilot !

 

[in_d_haus]

Yup! actually many racers come down and buy 110 octane av gas. and Rip, anyone can come down and buy some...

 

[Alex Baumann]

Yup! actually many racers come down and buy 110 octane av gas. and Rip, anyone can come down and buy some...

See Rip, I've told you. Forget octane-booster. Fill up with F16 gas and off you go :bigpimp: Seattle-San Diego in 3 hours !

 

[Guest84]

Which brings up another question: If you ran 110 octane, any chance of burning "too hot"?

 

[J. Kidd]

Actually, no....

No real risk of burning "too hot". All that octane does is make combustion more difficult (like an ignition retardent). Race cars use high octance fuels to prevent detonation (usually from very high compression ratios or super/turbo chargers - anything that will substantially increase cylinder pressure/temperature). I have heard rumors of cars that have used a very high octane fuel that don't need ended up damaging the oxygen sensors....but those are rumors....

I don't think you will see any benefits from using higher octane fuels in your car "stock". The computer will adjust timing up to a certain extent (I believe for 92-94 octane). I do not think the stock computer will advance timing any more than what it can achieve with that octane.

However, an aftermarket chip (or Shark Injector) may advance the timing further to take advantage of the higher octane.

 

[Nat Brown]

Re: Actually, no....

I tried this last year with my 97 540i. I bought a 5-gallon can of Union 76, 100 octane racing fuel and dumped it into the tank with about three gallons of 91 octane fuel. It made no performance difference, although I could swear the engine ran smoother.

I posted on bimmer.org, and it resulted in some discussion, but unfortunately the archive search is still broken.

As mentioned here, I'm told you would need to chip your car of otherwise modify the engine to take advantage of higher octane fuel.

--gary

 

[bol]

The biggest issue with octane boosters is the money factor.

A typical octane booster will raise the octane level on a tank of gas about 5 points, and higher priced onces claim up to 7 or 8 points.

5 points on a tank of 91octane is not 96octane. It's 91.5.

Is $10 worth a 0.5 increase in octane? nope. It's cheaper to mix in race gas.

 

[DougDogs]

I used to use octane boost in my Triumph GT6+ with excellent results

But, keep in mind this motor had no fuel or engine computers/management systems.

I tried it once in my '88 Daytona Shelby Z (intercooled turbo) and fouled one of the four injectors , haven't bought it since:thumbdwn: :thumbdwn:

 

[Guest84]

Thanks for replies/discussions guys..yeah, I used the octane booster in a 82' Virago 920 and it made a significant difference, but hey, it was a carbed motorcycle...

 

[Pinecone]

1) Boeing aircraft and F-16 burn Jet Fuel, which is basically diesel fuel. NOT good for your engine. Octane rating about 40.

2) Avgas is 100 octane, not 110 octane. And the ratings are different due to different operating conditions. Actually you can buy two grades of avgas in the US today. 80/87 octane and 100 LL (Low Lead). In the old days there was 91/96 and 100/130 both replaced by 100LL and the 115/145. Aviation gasoline has two octane numbers kind of like RON and MON for car gas.

3) All currently available avgas is LEADED. Use this and plan on replacing the O2 sensors and the cats. NOT cheap. OH, and you will have to drain and flush the entire fuel system to keep from destroying another set of sensors and cats. Unleaded avgas is coming.

Higher octane fuel does not clog injectors, not even avgas. If it did, there would be a lot of planes falling out of the sky, many aircraft are fuel injected.

Higher octane fuel is not harder to ignite, does not burn cooler, does not burn slower. It resists detonation. That's it. In another post I go into more detail about how it does this from a chemical point of view.

Running higher octane fuel allows your engine to produce the full rated HP at a much greater range of conditions. It doesn't mean you will get more HP, but you certainly won't get less. And int he right conditions you will get more than running lower octane fuel.

Now, as to octane boosters. They sort of work. But how well they work depends on the particular one and the particular gas you add it to. And the same brand and grade of gas is different in different parts of the country and different times of the year, even trying to test all the combos is almost impossible.

The concern with some octane boosters is not the injectors, but the O2 sensors. Some of the octane boosters over the years have used methanol as the primary ingredient. Methanol KILLS O2 sensors. And when your O2 sensor fails, the ECU goes to full rich running. This leads to excessive fuel consumption, excessive emissions, and poor performance.

 

[Guest84]

Good informational Post pinecone, you work in that business sector?

 

[Pinecone]

Good informational Post pinecone, you work in that business sector?

Thanks. No, but have done some research as a total gear head for many years.

I have found some good references and have a friend in the business.

 

[Pinecone]

Oh, and a lot of the info about avgas is from being a pilot and having flown many different aircraft from Piper Cubs to supersonic jets.

 

[in_d_haus]

Hey, rip plays a pilot on TV.... errr, a computer monitor that is...

 

[Patrick]

Which brings up another question: If you ran 110 octane, any chance of burning "too hot"?

I may be totally wrong about this, but I was under the impression that higher octane fuel makes combustion engines run cooler.

I also thought the reason for cars "these days" having lower compression ratios was due to the lower octane fuel, i.e., cut down on the compression to deal with the lower rated fuels so avoid over-heating.

Am I horribly mistaken?

I had a very radical 2110cc engine in one of my Beetles and I had the heads cut for a 11:1 CR. I found out quickly that unless I could find at least 99 octane gasoline, I would need to rebuild that engine about every 10,000km. Of course, heat is a killer in an engine that is cooled by air and oil.

Patrick

 

[Pinecone]

I may be totally wrong about this, but I was under the impression that higher octane fuel makes combustion engines run cooler.

I also thought the reason for cars "these days" having lower compression ratios was due to the lower octane fuel, i.e., cut down on the compression to deal with the lower rated fuels so avoid over-heating.

Am I horribly mistaken?

I had a very radical 2110cc engine in one of my Beetles and I had the heads cut for a 11:1 CR. I found out quickly that unless I could find at least 99 octane gasoline, I would need to rebuild that engine about every 10,000km. Of course, heat is a killer in an engine that is cooled by air and oil.

Patrick

You are mistaken, but not horribly.

Higher octane JUST relates to the fuel's ability to resist detonation, nothing else. It does not burn cooler, slower, faster, or anything else. At least not by virtue of higher octane.

The way a fuel is rated for octane may explain more to you. To determine the octane of a fuel they run it ina special single cylinder engine that has variable compression. ALL varibles are strictly controlled. Oil temp, RPM, cylinder head temp, intake air temp, etc. A side note, the different between RON (Research Octane Number) and MON (Motor Octane Number) is the difference in the parameters during testing. MON has higher intake air temp for one.

The engine is run on the fuel and the compression is raised until the engine reaches a certain level of "knock" measured by a Knock Meter (yes there is such a thing). Then the engine is run on various calibration fuels. Once they find the fule that knocks just a little more and the one that knocks just a little less, they know the rating of the fuel they are testing.

The calibration or reference fules are mixtures of n-hexane and iso-octane. These two were chosen for various reason. The % of iso-octane is the "octane rating" of the fuel. So 90 octane gas has the same knock reducing capabiltity as a mixture of 90% iso-octane and 10% n-hexane.

The reason compression ratios went down was due to the removal of lead, and the inability at the time to produce higher octane fuels with using lead.