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Illegal octane boost?

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Old Oct 17, 2023 | 06:02 PM
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Default Illegal octane boost?

Around here premium gas runs about $0.90 more than regular, so $10 or more per fill-up. So I bought a case of octane booster: https://www.lucasoil.com/product/octane-booster/. Twelve bottles for $95.00. Now I fill up with regular and pour in a 15oz bottle. Probably could use 1/2 bottle, based on info on the Lucas site. The car runs great.

What they don't tell you is, on the back of the bottle in big bold letters it says NOT STREET LEGAL

What's up with that?


Last edited by J. Kent; Oct 17, 2023 at 10:50 PM.
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Old Oct 17, 2023 | 10:02 PM
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You are going to want to google Methylcyclopentadienyl manganese tricarbonyl (MMT).

Car manufacturers will usually list any fuel or additive with MMT to be a Prohibited Fuel. The understanding is that prolonged use will foul emission components. There seems to be some debate about the legitimacy of that claim.

Either way, just put premium full at the pump. Shop around. by me some gas stations have a big 93 upcharge, others a lot less.
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Old Oct 17, 2023 | 11:54 PM
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^ I agree. So much easier to just fill up with a minimum of 91 octane each time.
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Old Oct 18, 2023 | 07:17 AM
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Label says it raises octane 3 points, so 87 becomes 90? My math indicates that $95 a case is running about $0.50 per gallon of gas. Is 90 good enough?
And in addition to possibly contaminating converters (assuming you have them) the additive adds pollutants to the exhaust, which the EPA and CARB disagree with. Makes me wonder what Techron consists of? Different chemistry entirely, of course, but undisputedly effective so likely to have a considerable volatile chemical content.

Last edited by redzg; Oct 18, 2023 at 07:28 AM.
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Old Oct 18, 2023 | 10:35 AM
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The extra cost for good clean 93 octane fuel around here ( 5 miles from Phila ) is pretty close to your price, but I won't let $10 stand in the way against using my 03 And protecting the emissions equipment. Even if it was a little more, I want my Corvette running right and do it safely ! JMHO

Last edited by killain; Oct 18, 2023 at 12:29 PM.
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Old Oct 18, 2023 | 11:26 AM
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Originally Posted by redzg
Label says it raises octane 3 points, so 87 becomes 90?
My understanding is "10 points" = 1 octane.
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Old Oct 18, 2023 | 11:41 AM
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Don’t play games. Just use the better gas.
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Old Oct 18, 2023 | 01:19 PM
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As others have said, just use premium gas. It really isn't worth the few dollars that you're saving. If you're going to be that cheap, just use regular gas without adding anything to it. The car will pull timing and will still run smoothly without knocking. It's not particularly good for the car, and it will have less performance. It's not something I would generally recommend. However, what you're doing now probably isn't much better, and may end up costing you a lot more than you're saving down the road.

As for why the additive that you're using isn't street legal, it's that it will violate emissions standards in many places. It's the same reason that catless exhaust systems are referred to as off road.
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Old Oct 18, 2023 | 04:13 PM
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Originally Posted by dom04abp
You are going to want to google Methylcyclopentadienyl manganese tricarbonyl (MMT).

Car manufacturers will usually list any fuel or additive with MMT to be a Prohibited Fuel. The understanding is that prolonged use will foul emission components. There seems to be some debate about the legitimacy of that claim.

Either way, just put premium full at the pump. Shop around. by me some gas stations have a big 93 upcharge, others a lot less.
I believe MMT will damage the catalytic converters. OP, if your area has 93 octane premium, and it's a buck a gallon more, you can do what I've done many times. When I fill up at a station where theres a buck a gallon difference, I fill up with half mid grade 89 octane, and half 93 octane, which gives you 91 octane. 91 octane premium is what the California Corvette owners must use. Good enough for them, good enough for me. I'll also add my built LS7 is running 11.3:1 static compression. If I tempt fate, drive stupid, and try accelerating hard in OD (A4 trans) without downshifting, say, at 1,500 rpm in 85° weather, I can induce a bit of spark knock even with 93 octane. Just use common sense, and don't lug the engine. You'll be fine. If you drive your C5 a lot, like 8,000+ miles yearly, like me, you can save some $$$ for sure. I do this because the 427 doesnt get better than 23mpg on the highway. Another argument for a blower!!! But that's another story........
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Old Oct 18, 2023 | 06:59 PM
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All good info. Thanks. I guess I trusted Lucas not to sell something that could do harm. Live & learn. I do think retailers (like Amazon) should let prospective buyers know the product isn't "street legal".
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Old Oct 18, 2023 | 07:38 PM
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Yep, MMT leaves behind a big orange residue. Coats the cats, O2 sensors, everything inside the engine. Do not recommend.
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Old Oct 19, 2023 | 02:32 PM
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Originally Posted by dom04abp
Methylcyclopentadienyl manganese tricarbonyl
Now THAT mixed with carbon creates a cocktail worthy of continued studying before I allow it to permanently coat the delicate surface of the gas gage sending unit.... gizmo. 🤨
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Old Oct 20, 2023 | 06:07 AM
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Many Oct boosters are made for older cars or racing car that have no emissions. So most are safe to use.

A number of things have changed due to Converters. Fuels and even our oils are not great anymore as they have had items dropped like phosphorus that used to preserve flat tappet cams.

Today to break in a cam we have to use additives on flat tappers. This is a big part of why everything went to roller cams and tappets. Less drag but also less wear due to the new oils.

my last flat tappet car I use a racing oil now as it still has high content. Even if it wipes out a converter at some point it is better than replacing a cam. It is a car not driven often so it should live.
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Old Oct 20, 2023 | 07:52 AM
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Since the label says NOT STREET LEGAL would that not let you return this product for a refund?
Although it appears you have already used some so guess that could interfere with a return if you bought it as a case purchase.
Any hot rodders in your area with a “pre-catalytic converter” engine that you could pass this on to?
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Old Nov 10, 2023 | 08:50 PM
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Originally Posted by dom04abp
Either way, just put premium full at the pump. Shop around. by me some gas stations have a big 93 upcharge, others a lot less.
Very true.
On the Jersey Shore, probably pretty typical for anywhere else, the prices posted out front are the low prices for cash and credit regular 87 octane.
So you see the one with $3.13 posted and roll in figuring the 93 will be cheaper there too. Nope, probably as high as $4.69.
Then you hit another station where regular is posted at $3.29 and you find their 93 is 3.99 !
Then only a couple miles away a station of the same brand has completely different pricing.
Tough part is with most you can’t read the price on the top of the pump until you roll in.
If it was only a buck or two I would deal with it but when you buy 15 gallons or more that could mean throwing away an extra $10 needlessly.
Ya I know I can easily waste that $10 on something stupid but I feel we’re already being extorted when we go to the pump, I don’t want to give them one penny more than I have too !

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Old Nov 10, 2023 | 09:50 PM
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I just use non-ethanol 93. I don't care if it costs a few pennies more.

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Old Nov 10, 2023 | 10:00 PM
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Octane boosters are historically a joke.

I use department/grocery store gas and make well over 600 wheel horsepower safely.

I have no desire to monkey around with stuff in a can.

If I want fake race gas I'll go buy Avgas from a supplier at the local airport.
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Old Nov 10, 2023 | 11:08 PM
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Originally Posted by Lt.Mike
most you can’t read the price on the top of the pump until you roll in.
Gas Buddy will show you prices, you don't even have to go anywhere. Waze used to, haven't used it in a while so that may have changed.
Originally Posted by grinder11
I fill up with half mid grade 89 octane, and half 93 octane, which gives you 91 octane.
Grinder, how do you make sure the mix is the same in both tanks when you do this?
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Old Nov 11, 2023 | 01:58 PM
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Originally Posted by Dads2kconvertible
Gas Buddy will show you prices, you don't even have to go anywhere. Waze used to, haven't used it in a while so that may have changed.

Grinder, how do you make sure the mix is the same in both tanks when you do this?
Sorry for late reply. I did think of that, but so far I've had no issues doing the following; I pump in about 8 gallons of midgrade first, then the rest, the 9-10 gallons of premium last. It seems to work great. I have a real time scan tool, and theres no KR on the mix, unless I lug the engine, which I only did once to test the KR on the 89/93 octane mix, and I did get a small amount. However, when I also tried that test a second time with Shell 93 Premium, it still did the same thing. Bottom line is we shouldn't lug any engine, regardless of fuel octane ......
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Old Nov 11, 2023 | 03:03 PM
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All Octane Booster-in-a-can products are a waste of money. If that stuff actually worked, for less money that the usual additive packages do, the oil companies would add it to their existing fuels There are no new chemicals is this world, everything we have today, we've had, and studied for 50 years.

Adding 104octane boost to a tank of gas t, will at best raise the octane of your fuel 0.04 octane (also known as 4 points).
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