Octane Booster vs 100 Octane?
 

I just found a gas station a few miles away from my house that sells 100 octane gas, and it got me thinking. I have ~20 gallons of 91 in one of my tanks (45 gallons each). I put that in back on Jan 2nd and the boat has been sitting since (indoors mostly if that even matters). I could put a bottle of the Lucas ocatane booster in the tank (~$11 and treats up to 25 gallons), or put a couple gallons of 100 octane ($8/gallon).

For u gas guru's, is there an advantage to one option over the other? Thinking of getting the boat wet tomorrow. Will be a relaxing day so I wont be railing on it, but was just curious. Any thougts?

Btw, its a blown 540.

Mmmm, nothing like the smell of race fuel in the morning! Go with the real deal.

Fill the tanks full of 100 octane. Good fuel is cheaper than tearing up a motor.

Octane boost = joke
Race fuel = good smell

you will go faster with booster in your tank :party-smiley-004: it says it on the bottle

have no idea what your engine requirements are? power on pump gas is the way to go. buying race fuel from a local station you will find is all over the map. many sell kerosene in the winter from the same pump...it is not regulated because it is ORV fuel....the fuels at the pump are pretty accurate and i think the test results are public from the DOT in your area. this way you can find your local VP dealer and buy 55 gal drums and mix yourself. having consistent fuel you may find you only need 95? i found a VP guy that mainly sold to MX guys and when i was buying hundreds of gallons at a time he was very open to totally giving me a killer deal.

to answer your question you can raise the oct # by all different methods. some better than others. some do the job but leave tons of deposits. VP is now making econo fuel that is designed not to leave deposits like pump fuels do....u may want to check into that!

Majority of octane boost raises Octane POINTS.

There are 10 Points in an Octane Number. Octane numbers are 87 89 93 etc.

So if the can says "increase octane 8 points", added to 87 would be 87.8

The higher the octane fuel added the less the increase

Race gas mixed with regular fuel is much much better, especially for a boat that holds large amounts of fuel.

From my research years ago the best octane boost I could find was the NOS Racing formula octane boost. Increase of 60 points or 6 numbers (when added to 87 octane).

Thanks for all of the great info guys! Im gonna go swing by the station and put in the 100 octane in the morning :)

X2

Save your money for plugs if you need higher octane.

Assuming it needs 91 octane, I would put 5 gallons of the 100 octane in each tank.

Increasing the octane too much will most likely cause the plugs to foul and will definately make your transom black.

Pump the gas out into your truck or car and start over.

Take out all the old fuel and run your first tank with straight 100LL. Top it with 100LL before your last run, and top it after when putting away for the winter. It is much better on your fuel system than pump gas. It has no ethanol, I can't believe nobody mentioned that yet.

Its only 2 month old fuel. Adding 5 gallons of the 100 octane will be more than adequate.

I only run 100LL, nothing else, but I can write it off, so it ends up being cheaper than pump gas at the marina. Love the smell, and the internals are always very clean when the engine is opened up.

Couldn't running 100octane be harmful to your engine if your engine was only designed to run on 91?

Nope just more expensive.

Good to know.

and you will actually lose HP if the engine was designed to run on 91 octane. You should also really add some Marvel's Mystery oil to it fi you run it straight.

Why marvel??? The valves love the lead......

This is from another thread.....

It seems like a lot of people on here say i heard from so and so dont run it or i heard so and so blew a motor while running it. But, when you talk with engine builders they say it is far superior to any pump gas. With that said it is in no way race fuel, but if youre on the verge of pinging with 93, the 100LL will keep it from doing so.....

I believe because AV gas is considered a "drier" fuel than pump gas.

Two onces per 10 gallons. ;)

I've been running 33% 100LL AvGas for the last five seasons. I really don't know if I'm wasting money or not..... but nothing has broken, I've had no fuel related issues and that makes me happy. I'm sticking with that formula. :eureka: :D

I hear ya, I run it in everything I have that doesnt have an 02 sensor. Never had a fuel system problem and most of the toys sit for 6 months to a year between uses........

Yep, I run it (straight, not mixed) in my Gator, lawn mower, weed whacker, generator, wife's Honda Ruckus and my old Vette (that never gets driven), etc.....

That beats the chit out of rebuilding carbs!!!

Street legal race fuel from Union 76 (100 oct.) has high alcohol content. Put some in my cobra one day and that biotch ran way lean.

Back in the 80s I ran 100 LL av gas mixed with 89 reg octane. This mixture was tested by gulf labs and came out to be 95 octane. I mixed 5 gal reg to 1 gallon av gas. I ran two blower for years and never had any issues. It was just a pain pumping the ave gas from a drum.

we are on an airport, so no problem, just pull the truck up :coolcowboy:

Its because it is considered a much "drier" fuel than race fuel or pump fuel.
This probably explains why engines that you have run it in are so exceptionally clean inside.

+1. My '63 Caddy LOVES it some 100LL :grinser010:

One other note with the av gas back then is not everybody could get it there wasen't any road tax on it.

Just treat all shoulder/off season fuel with stabilizer. Much cheaper and easier.

I have gone to Conklin's fuel treatment/stabilizer year round for my power equipment.
Most boat tank fulls too except the peak season I know I will be burning though.

Something also to note is that I am pretty sure that 100LL is 100 octane on the Motor Octane Scale which is around 105 octane on the R+M Octane Scale. The R+M scale is the octane posted on the pumps at gas stations.

Running 100LL in my supercharged motors with absolutely no issues. Last year the 100LL was $5.10 a gallon and the marina was the same price for 87 Octane. Teague told me to mix one pint of 2 stroke oil w every 50 gallons. Yes, the motors seem to run very clean on the 100LL. I would rather run good fuel than the garbage at the pump.

....obviously you have not been talking to 16 year olds driving the chit out of their mothers Honda's or Hyundai's......

The airport that I go to gets a data sheet with each load. It is usually between 106-112. He showed me something neat one day when I asked about it being "dry". The guy took a piece of paper and squirted some 100LL on it. It dried and was gone in about 5 seconds and left no stain on the paper.

We use it as parts cleaner, and also to clean everything before assembly. Dip your part in a bucket of 100LL and blow it off with a blow gun, clean as a whistle. We get a lot of it for nothing because all airports are required to sump a gallon out of each tank every day to ensure there is no water in the tank. Something else to take note of is that water will NOT mix with 100LL like it does with ethanol. It drops straight to the bottom.

Is that 106 to 112 on the Motor scale or the R+M scale?

I found this with a Google search
http://www.race-dezert.com/forum/sho...k-to-run/page2
"Re: 100ll Avgas Ok to run?
Real info on Race Gas/Av Gas...

My experience comes from 7 years as the western states representative for 76 Race Fuel, Unocals 40 hours Advanced Products course, Working personally with Tim Wusz (senior performance products Rep for Unocal, Tim was responsible for Unocals race fuel development for 30+ years). I have also met and discussed fuels/motors with just about every engine builder in every facet of racing in the western United States. I also conducted Educational Seminars at the Fred L. Hartley Institute in Brea in which we would invite Engine Builders for a tour of Unocals testing facilities and do live octane tests on any gasoline they would choose to bring to the seminar. Included in the training we would demonstrate live tests how Distillation curve, Reid Vapor Pressure, Specific Gravity, Octane Rating, F;ashpoint, etc are conducted and the importance of these numbers. Some of you will remember me from contingency with my 76 Racing Gasoline hospitality trailer in the 1990's.

Through the 50's, 60's, 70's and 80's Av gas was the base product used for most racing "gasoline". VP, f&L, Turbo Blue, and Trick all used AV gas as the base product. They would buy a tanker (8000 gallons of Av Gas) than add other hydrocarbons/TetraEthylLead (TEL) to the base, drive around the block stopping and accelerating the truck/trailer until they felt the product was mixed well. Obviously this was not science, but it worked for most racers only because most racers use a higher rated octane than they actually need.

In the mid to late 1990's VP graduated to buying there own base product and do there blending of products in a much better fashion. Turbo Blue and Trick have since been bought Sunoco and are blended by Sonoco. Trick was purchased by Phillips 66 and has continued to be blended by Phillips 66.

The only two companies I am aware of who "cracked" there own base product is Sunoco and 76. And as we all know, 76 race fuel is no longer available, leaving only one true manufacturer of Racing Gasoline....Sunoco.

AV Gas has a MOR (motor octane rating) of 96, R+M/2 rating of 100, and ROM (Research Octane Rating) of 106.

AV Gas is lighter than racing gasoline thus more fuel/larger jetting is required. Jetted correctly you should not experience a lean burn at WOT.

I would not use AV Gas as a cleaner. The amount of TEL (2 grams/gallon) and other hydrocarbons makes it extremely carcinogenic. Same goes for all other racing gasolines.

Shelf life is NOT better. The reason pump gas won't last as long is because street gas has extremely lightend hydrocarbons to help your car start and idle. Racing Gasoline does not have these light end hydrocarbons needed for idle and starting, hence the reason race motors start and idle poorly.

Av Gas is NOT designed for low RPM motors. AV Gas is designed to not detonate/preignite causing detination. This would be the same design as race fuel. If you compare the "distillation curve" of AV Gas to Race Gas, you will find they are almost identical. The "distillation curve" controls the speed of burn across the combustion chamber.

You will only "spit" gas out the exhaust pipes if you run to rich or include a supercharger/turbocharger on your engine and "overdrive" the blower. Example would be the *****in flames you see at the starting line of a drag race on normally aspirated engines and the long flames you see on all "blown" engines.

The LEAD (TEL) added to AV Gas is to increase the octane rating only. All heads these days have harden valve seats. There is no need for lubrication of the valve seats. All engines have come with harden seats since the late 60's.

AV Gas is not formulated for High Altitude. and will have very little, if not any performance differences vs racing gasoline. On the other hand, commercial grade fuels (87, 89, 92) will definitely enhance your performance due to the commercial fuel being oxygenated. The Oxygen enhancers added to commercial fuel is only for California Smog laws.

Advancing timing on your motor will definitely help with AV Gas and Race Gas due to its slow burn characteristics. On the other hand, be careful if your running commercial grade gasoline, more timing can cause detonation/preignition quit quickly.

AV Gas does not go BAD faster. It is extremely consistent. The MOR is only 96, whereas Sunoco Purple or VP C12 is 104. A rating of 96 is good for up to 10:1 on Steel heads and 12:1 on Aluminum heads with water cooling. Air cooled motors run much hotter.

Buying a higher octane for a $20-50K motor is the cheapest insurance available.

Remember this...OCTANE is a measure of a fuels ability to resist detonation/preignition. The higher the Octane number, the slower the fuel burns. Technically speaking 87 Octane fuel will develop more power than 118 Octane fuel. With this said, you should see gains in throttle response and HP by mixing commercial fuel and AV Gas/Race Gas. You now have some light end Hydrocarbons for throttle response and heavy hydrocarbons/TEL for detonation resistance.

Bottom line... use the most consistent fuel you can find and create horsepower by moving as much air as possible though the combustion chamber.

I have no reason to be bias here as I have moved on to much greener pastures. See you on the race course.

Good Luck,
Steve Poole"


Apparently Steve Poole knows his sh!t

Looks like the 100ll is some pretty good stuff....