Now I`m a bit confused and don't want to hurt anything and I street drive w/91 Shell sometimes and wanted to race w/av gas so maybe I'll stick w/the 101 VP-101............

your not gonna hurt anything trying it maybe just your pants pocket you keep your wallet in.like the other post said go check out yellowbullet tons of guys running it with good results.it also dosent change my tune at all from c12 or sunoco112 or anything else ive tried non-oxygenated only when i run q16.airplanes take off at sea level so the altitude thing is BS.....they have way more load on them at take off.

your not gonna hurt anything trying it maybe just your pants pocket you keep your wallet in.like the other post said go check out yellowbullet tons of guys running it with good results.it also dosent change my tune at all from c12 or sunoco112 or anything else ive tried non-oxygenated only when i run q16.airplanes take off at sea level so the altitude thing is BS.....they have way more load on them at take off.

Like others have said already, there's so much BS on this subject it's ridiculous. I have run it many times in cars or motorcycles in the last 45 years. It always et's better than pump gas for me. I haven't seen any ill effects. Years ago avgas was better but at Keith Blacks that is what we used on the dyno.

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 bitchin 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

Well, I live at 5000 ft above sea level. We have a great 5000 ft runway at our airport. Most of the planes that frequent our airport are powered by air cooled engines making about 2-300HP ( at sea level)- not 6-700 HP. Got plenty of air running over the engine and related fuel system on the ground. I also belong to the local car club ( also at 5000 ft above sea level ). Most do not run Av gas. Those that do, run a pump back by the fuel tank to keep the fuel line pressurized - to prevent vapor lock. Obviously KOS has never experienced this "phenomenon" and just blows it off as BS. Rooky! Did I mention heat soak problems when running Av gas? If you think E10 is bad, let me know how long the crank time is with Av gas sitting in them float bowls - or should I say - aint sitting in them float bowls after the carb heat soaks for an hour or so.

Let me see if I can steer this thread back in to some form of reality. First, it's interesting to see how so many fall back in to the mind set that a higher octane # = more power. The real BS comes when someone tells you that they changed fuels ( with no other changes )and made more power. In most cases when that occurs, they had problems that they did not know about with the fuel they were running, and the most likely cause was mild detonation that they could not see, hear, read, but was there.
In the late 60's I worked for a company called "Universal Oil Products". I worked in their dyno shop ( both engine and chassis) for 3 years. Attached to this shop was their Knock lab, which consisted of a bunch of single piston engines that you could vary the CR on while they were running to measure the anti knock ability of different fuels. On the dyno side, we ran the same fuel for almost all of our tests - 100 iso octane or 100 octane. We ran engine dyno tests for lots of different reasons and some were for detonation. If I were running a dyno shop today for high performance engines I would definitely use a high octane fuel to do my testing. Av gas would be a good choice because you don't have to worry about RVP and you could maximize other engine parameters, (timing, temp, AF ratio, etc ) without accidentally grenading the customers motor, and the costs might be better than race gas. There was seldom a time when we changed fuels on a test engine and saw a change in HP without some form of detonation involvement - why the detonation lab was attached to the dyno lab.
Getting back to RVP, I am sure everyone knows that RVP is a measure of fuel volatility (how easily it vaporizes) measured in PSI. The higher the #, the more volatile. Race fuel is usually in the 5-7psi range. Pump gas = 12-14 psi range, and Av gas is well above that. As long as you can control the ambient temp ( dyno work ) or are using it in a seasonable temp range ( ambient and under hood temps) it probably won't be a problem. Running Av gas in a car with high under hood temps ( street applications)and dead head fuel systems and you stand a good chance of experiencing vapor lock. Transversely, running race gas with a low RVP and trying to start at 0 degrees F, could be a problem - why I didn't recommend it for street applications. Again, to the OP, it voodent hurt to try it! If you see an improvement in ET / speed, great, but you were probably running in some level of detonation prior to the change ( albeit it minor ). Objectve = stay out of detonation at all costs while running a fuel with the lowest octane rating where you can do that while maximizing all other engine settings for best TQ/HP. My opinion = play it safe and run a little more octane than you think you may need.

ive been running av for 30yrs never experienced any vapor lock valve seat issues etc....have you ever run it?? if you dont have first hand experience with it dont come to conclusions from what you heard.