[quote=“J&J,post:11,topic:33900"”]
100 LL AVGAS is not the best thing to use in a street car especially at those prices
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Your common Avgas is 100/130LL (low lead) is dyed with a blue tint. There is also 100/130 that is green. IMHO, you can run or mix it in your car with little fear of damage if you use some common sense. The real time to consider its use is if you have a blower or turbocharged application and you can’t get the proper octane rating from another source. A plus for avgas is that it is consistent from batch to batch and very clean. A negative aspect is that if you run straight avgas you will notice increased fuel consumption due to the lower BTU content per gallon.
Aircraft piston engines normally have locked in timing at 20 to 25 degrees. At all rpm’s, even turbo engines. What an airplane or a helicopter has that your engine doesn’t is a mixture control. Full rich at takeoff and leaned out cruise. That is why the dual octane rating. Av gas is more stable at altitude. We run at lower field elevations. Higher Baro pressures at our level at the ground. Therefore aviation fuel doesn’t vaporize as well. Causing a lean condition but without the detonation because of the octane. But you will have the sweet smell of a race fuel. You can richen up the accel circuit in a carb., richen up the jetting to compensate. That is all you will do. The power? Only the timing system at the drag strip will tell. I have tried to explain this in simple terms. Correct me if I’m wrong. Been there done that. And gave it up.
Don’t believe the Urban Legends that surround this fuel. It doesn’t make economic sense to use it in your daily driver, but if you have a boosted toy or high compression application it is an option to get the octane you need via blending.
I have no doubt that true “Racing” gasoline would probably be better to use in an automotive application, but you have to look at your specific situation (fuel availability/economics/application).