View Full Version : Is Avgas Safe to use

01-04-2005, 10:34 AM
We only have 90 Octane fuel here so I was wondering if 100LL Avgas is okay to use in conjunction with 90 Octane 'premium'. I believe my GIAC chip likes 92 Octane.

01-04-2005, 10:54 AM
Remove your cat. It will cook your O2 sensors also. Low Lead Av gas makes mad power for 1/2 the cost of unleaded race gas.

01-04-2005, 10:56 AM
I've read in numerous places that cars should NOT use aviation fuels. I personally wouldn't but then again I don't know enough about them to make a strong case so take my advice for what it's worth.....$0.02

*edit*-I'm asuming your talking about aviation fuel. otherwise I don't know what the hell Av gas is.

01-04-2005, 11:09 AM
Avgas 100LL is 100(Low Lead) Octane Aviation Fuel.
Would it still cook my sensors and cat if I only mix in 5 gallons per tank?

01-04-2005, 02:41 PM
After doing some reading I guess I wont be using avgas.
Here is an interesting article talking about it.


01-04-2005, 03:08 PM
woohoo! I just found a place that sells racing gas. 108 and 113 octane. Now I can get the good stuff for my bike and my car.

01-04-2005, 03:20 PM
Originally posted by oface
woohoo! I just found a place that sells racing gas. 108 and 113 octane. Now I can get the good stuff for my bike and my car.

Just make sure that the 108 and 113 octane fuels are "unleaded" unless you plan on running without a cat. I actually run Sunoco 110 Leaded in my car at the track since it only cost me $4.50 a gallon plus tax. When looking at race fuels dont just look at the (R+M)2 rating of the fuel, it is more important to look at the Motor Octane Rating.

01-04-2005, 03:27 PM
haha avgas means exhaust fumes in swedish, it's what comes out of the car, not what you put in.

01-04-2005, 03:46 PM
I'm pretty sure in the U.S. it's short for two words. av= aviation, gas= gas

It's pretty expensive here. 43 bucks for 5 gallons. a 55 gallon drum is 360.25 for 110 octane.

So does anyone object to mixing it like this?.... mix 2.5 gallons of 113 race gas with 12.5 gallons of 90 octane pump gas... it should give me 93.8 rating. which is a little more than I need. But maybe I'll try it out for a while and then just add more pump gas if needed.

01-04-2005, 05:11 PM
you should be able to mix it... try to mix unleaded with unleaded.. you can get 105 and 110 unleaded race gas ... you would be better off mixing 105 and 90.

I used to do it to lower the octane - as in 2-stroke, the lower octane level would produce better top end performance - but under load it would detonate fiercly, so since the stator and ignition modules were spec.. we mixed gas to find the best balance.