Octane Booster - Beware

[davepl]

I almost jumped into the "Where to find ethanol-free gas" thread because in there someone said buy 89, add some booster, and you're right back to 94.

Not so.

Read the label of ANY so-called 'octane booster', and all they do is remove deposits in the combustion chamber that would otherwise cause an increase in compression ratio and possible detonation.

Even worse, when it says "Raises octane 4 points", that means RIGHT of the decimal. From 89.0 to 89.4. Not 93.

I can't believe the FTC hasn't punted these things from the market twenty years ago.

[JointTech]

lol, ive seen 100 car and science shows where they debunk that crap.

I also suspect its placebo. Added Octane in an old engine doesnt make it go any faster if it isnt built for high compression.

the higher the octane the LESS explosive it is.

Though to be fair we used to fill up my dads old truck at the airport and it felt faster to me. lol

[mmiddle]

There is some stuff on the market... I forget the brand now, but I run it in my boat that is lead replacement. Chemically it is lead additive that used to be in car gas years ago. If you run it in EFI engines it will trash the O2 sensors. Yes it does work quite well. The same Chemical additive that is in this stuff was in a product back in the 80's called Octa-max. That stuff was like rocket-fuel.

I agree that most every product that claims to boost the octane is a scam. Read the labels and know what chemicals are just cleaners and which are actual lead additives that actually boost the octane.

I know this is adding power for my boat 20' CrownLine by the difference in wakeboard pulling. And by the way... most "Marine gas" is regular car gas. Ethanol and all...

[zeldman]

A long time ago I was very active in round track racing of all sizes, and to support my addiction... I mean cars... I also had a race fuel business. Sorry to say this but a 12 ounce can of anything (except nitro) will not turn ordinary gas into top quality race fuel. And the EPA does not care how good gas is made, they just set the level on how bad you can make it. And it has been just above that limit for many years now, ever since tetra ethyl lead was permanently removed from auto gas. Nitro cost me $1200.oo for a 55 gallon drum in 1990, so you can guess how much I charged customers for just a gallon. And yes, I know who and how "other people" (my story and I am sticking to it) cheated on fuel and beat the specific gravity test.

[motorcritter]

There used to be a 'lead replacement' additive I used on my Nortons, years ago. I haven't seen it for about 20 years (at least). I had hardened valve seats installed to get around the potential problems. I ran AvGas hi-octane stuff in the souped-up Norton (12+to1 compression), and/or race gas, with good results. I run premium no-lead in the Triumph I have now, but its only 9to1, with upgraded valve seats. I haven't bothered to run anything but premium no-lead in the Cheyenne 402, it'll diesel otherwise. When I put AvGas in the Harley FLH I had, all I got was cleaner plugs. It was about 8to1, IIRC. Fuel is going to be more problematic, as years go by. The Rice-Rocket guys I talk to are setting their cars up to run on E85. I might do the same, the bike will be easier to alter than a truck, and give me an idea of what to expect.

[davepl]

I've seen lead replacement as well, but when Tetra-Ethyl-Whatever real lead was removed, all you could buy after that was a lead substitute, which really only even claimed to help protect valve seats, nothing with octane.

I think it's a safe bet that increasing the octane rating in fuel isn't cheap. I think another safe bet is that increasing R (Research) isn't the same cost as M (Motor). Forgetting for a moment which one is most important for detonation, you could probably increase the other by 50%, which increases octane ((R+M)/2) by 25% with no real benefit. So to expect something which can increase the octane rating of 20 gallons of base fuel, if it were cheap, it'd already be there and your little Chevron cars would be talking about it in TV commercials. Doesn't exist.

"As most of you on this thread seem to already know, but for the benefit of those that don't (TM-Dave)", increasing octane doesn't make a fuel more powerful, it just allows it to be used in an engine with a higher static compression ratio to extract more power with that higher compression. Increasing octane where it's already sufficient would only dilute the fuel.

Imagine that you could add water to gasoline to increase the octane. Would you want the 90/10 gas-water split or the 80/20 gas-water split? I'd bet you'd want the one with the most combustible fuel in it, subject to it not rattling in your engine. Just because (in our imaginary experiment) AV Gas was 70/30 wouldn't make it more desirable, unless you were at a high altitude or really needed it for forced induction or high compression. But your mom's car wouldn't go any faster at the track with it.

And lastly, in some cases, an aggressive engine management computer can (and many do) add timing until the engine rattles, then backs it off, and tries again periodically to increase it. Some keep long term averages. Some will rattle each and every time but pull out a different amount of timing in response to rattling. There are a number of different strategies, but here's the net:

- Many high end engines (new LS7, old LS-7, last-gen M3, etc) use compression ratios that could probably take advantage of up to some number like 93 or 95 octane.
- The old engines (1971 LS-7) will just rattle and fail without enough octane
- The new engines (2007 LS7, M3) will back timing off at a performance cost until its safe

But there is never, ever, as far as I can imagine, a case where an engine (in proper tune and without deposits) that was not pre-detonating and that wasn't computer controlled where more octane was -ever- better. Maybe if your grampa had dialed back the timing on your grandma's LS-6 you could return it to original spec with proper fuel.

And since this is a long post anyway, don't get me started with people who don't like the smell, or can't tolerate ethanol, or who think gasoline was just plain better in the olden days. I like the way my Dad's hardware store smelled on the spring mornings of the 1970s as well, but I don't claim his fertilizer was any better than current stuff, because I don't have any numbers to compare. But I'd like to, because I'm curious.

Unfortunately, the level of discourse on that topic can best be summed up in last month's Hemmings Classic Car editorial wherein we learn that gas was blue. Which is apparently a good thing. Which I was happy to learn, because our unleaded here (WA State) is also blue.

Where I grew up (Saskatchewan) farm gas was cheaper, I guess because there wasn't a road tax on it. So the farmers always wanted to run it in their cars and truck for going to town, but didn't want to get caught with "purple gas". So they'd put it in glass jugs on the porch until the UV rays of the sun bleached it out. And these were people with $200,000 John Deere harvesters, so I have no idea what lengths the poor people would go to... Actually yes I do.

[BlacklandCamper]

Moth balls.

Only on engines you don't depend to get you to work.