When using AV gas in a car don't you need to add some oil to it? And if so how much per gallon? I remember we use to put it in a race car and added some two stroke oil to it. Its been awhile.
Thanks

Don't use AV gas in your car. It will destroy your O2 sensor and your catalytic converter. AV gas contains lead octane improver. Some do use it in race engines, but that is going away as well. It is unlawful to use any lead based additive in cars or trucks.

Even Nascar is switching to lead free race gas.

#1 You didn't answer my question.
#2 This is for a older car That was made for leaded gas.
#3 I get this fuel for nothing.
#4 Why do people have a need to make things more complicated? I just asked a simple question.

What was the reasoning behind putting 2 stroke oil in it?
was it that you thought avgas was missing some lubrication that mogas has?
was it that no matter what gas went into the racecar it needed a lubricant?

From what I have read, avgas is not a good substitute for race gas although it is widely used for that purpose. I do know it is formulated for conditions that are not found in ground vehicles. It would not need 2 stroke oil added for use in a car, the lead in the fuel takes care of that.

Lead would be lubricant enough, even when mixed with unleaded fuel. A lot of pilots will use MMO or other additives as an attempt to ward off lead deposits, but not for added lubrication.

You might be thinking of alky fuels, which do run dry and can benefit from some lubrication to "pickle" the motor when it's not being run.

Thank You Mister Wiley

As far as formulated race gas vs. av I can relate my limited experience with some stuff I've played with. AV or a mixture of AV does a great job of warding off detonation in high compression or high boost applications. The engine makes more power because of the high combustion pressures, not the fuel. The same motor on a more specific race fuel can often make a few more hp, but not from the octane, but from the oxygenates in some of the race fuels. For example I've seen the same power with 110 leaded race as I have AV, but found a few more using 105 oxygenated when the fueling is adjusted for it. AV is so much cheaper and works fine that unless your after the competitive edge of racing it can save you a few bucks. It's filthy with lead though, even though call it 100ll (low lead) so mixing it with pump unleaded to a point where your motor can tolerate the octane is usually ideal.

The point about using some percentage of Avgas is not what it will do but rather what it will let you do. You can run a higher compression ratio than is usual with normal pump fuel.

"#1 You didn't answer my question."

Did the best I could with the info you provided...

"#2 This is for a older car That was made for leaded gas."

You didn't say that. Knowing that would have changed my answer.

"#3 I get this fuel for nothing."

That's nice. Doesn't change the fact that it is against the law to burn any leaded fuel in an auto. Even ones designed for leaded fuel...

"#4 Why do people have a need to make things more complicated? I just asked a simple question. "

See answer #1.

I should have added that I personally have never used UCL in my various cars with over 58 years of driving. I don't plan on doing so now, although I do use FP60.

In my several years of flying I have heard the some operators use MMO in their av gas. I would never use it myself as it is not approved by the FAA.

Avgas (100LL) is often the base for race gas. Many race gas companies won't tell you this.

Using something like a blend of Amoco 93 octane unleaded and 100LL results in a product that works very much like "old school" premium leaded gas. The lead response ratio of various unleaded fuels is different by batch and brand. However Amoco ult is supposed to be transported by a dedicated method and should therefore be consistent.

The addition of a small quantity of leaded fuel (with plenty of lead, like 100LL) raises the octane (lead response ratio) of unleaded more than you might expect. As a guess, 10 gallons of 93 + 1 gal of 100LL might result in 96 octane. A big jump for such a small quantity of additive.

In any case, 100LL contains plenty of lead and will lead to spark plug fouling in some cases. Especially if an engine spends lots of time at idle.

100LL is a very high quality fuel and is very consistent. Therefore, an engine tuned to run properly on 100LL can be expected to perform well from week to week and year to year. My lawn mower and pressure washer, which are tuned quite lean from the factory, run better on 100LL than on unleaded. My echo weedeater makes a bit less power on 100LL and runs more crisp on unleaded. My scooter and 2 stroke dirt bikes also run a bit more crisp on unleaded than on 100LL. YMMV

Chris

The two grams of lead in 1 gallon of avgas diluted in 9-10 gallons of Amoco premium would only raise the R+M/2 octane maybe half a point. Unleaded auto gas is not very lead sensitive due to the fact the aromatics and olefins are not lead sensitive.

Ed

Avgas (100LL) has a lower flash point but it actually burns cooler then auto gas and longer. It will still be burning when the exhaust valve opens burning the valve. Also it is does not have a 100 octane rating. It is calculated differently then autogas.
http://en.wikipedia.org/wiki/Octane_rating[/url]

Avgas does NOT burn more slowly or cooler than auto gas. It has slightly less energy per gallon than auto gas. The important octane rating of avgas is the Motor octane which is a minimum of 100. Octane is simply the resistance of a fuel to non spark (compressional) ignition.

From Wiki "Octane rating does not relate to the energy content of the fuel (see heating value). It is only a measure of the fuel's tendency to burn rather than explode."
is not quite correct.

Ed

Hi Ed,

When I was playing around with Turbo cars, Avgas added in somewhat small quantities to 93 made quite a difference in detonation resistance. Much more than 1/2 point.

The Link ECU setup I was running would display knock events and had an adjustable knock threshold. As it was a calibrated system, I could "adjust" the engine accordingly. On the fly if needed. As I mentioned above, the results were clearly along the lines of 96 or so in my situation.

I live right next to Moroso (now palm beach motorsports park) and race gas is quite plentiful here. Even the local Sunoco has a race gas pump!

So, I am not disputing your knowledge. But, the fact remains, I had good results.

Chris