I know airplane fuel is around 106 to 108 octane but it's leaded. it's also cheaper than 93 octane around here. If i'm not running any cats, would it hurt to run leaded fuel? also anyone know how stable the gas is at low altitude? i mean my car is fast but no where near flying lol. just thought i'd get some advice before i go out to the airport and see what happens.

 

First good luck if you can get the gas in the car, usually airport security or personal is pretty strict. 2nd I wouldnt suggest filling the car with this because you will kill your o2 sensor. Mix it with regular gas but dont fill it. Whenever I got the extra cash I add about 5 gallons to a 3/4 tank of 101 LOW LEAD Aviation Gas. I have a gas station that provides it at the pump for the air boats =P.

 

2 more questions, why does it say exhaust leak under my name and where is my sig?

 

I'm surprised to see that it's cheaper than 93. When I used to occasionally run it in my bug it was like $2.45/gal for 108. That was 10 years ago or so.

The lead will also ruin your O2 sensor. If you don't care much about it, or don't run one then you should be fine.

 

i've got friends that fly and can get all I want in 5 gallon gas cans. so thats not a prob, I was just wonder the effects of leaded gas.

 

Leaded gas = dead 02 but your car will feel extremely smoother and little to no knock underboost. Honestly I think 108 octane is overkill. I mix the 101 with 93 and usually I notice the difference right away.

 

Like other people said it will kill your O2 sensors. Most race gas companies like VP recommend 104 for street/strip unleaded 76 Unocal is 100 if you get too high of an octane the fuel burns too cold so unless you run sick amounts of boost you shouldn't need that high of an octane.

 

Because your a newb.

 

Hey hey give him a chance =P

 

Hey, what's up. I fly in Temple and Killeen and have been thinking about putting some in my car. We run 100LL (low lead) in the cessnas, but it costs ~$2.20/gallon.....how is that cheaper than 93? The 93 is about $1.50-1.60/gallon and is good up to about 17psi. I was just interested in the 100LL to tune safely for 20psi and see what I could trap in the 1/4.

Where are you getting this cheap 106 or 108 from?

Shoot me a message sometime if you want to get together or if need help.

 

Low lead aviation fuel is not near the same as unleaded auto gas.

"Low lead" means just that: less lead than "regular" aviation gas. It still has much more lead than unleaded auto gas and is therefore unsafe for cars that need unleaded gas.

 

the biggest deal is that it kills the catalettic converters... the stock o2 sensor sucks ***** anywyas and when it does go, "if you even notice a difference" you can pick one up for about 20$ online

"dead 02 but your car will feel extremely smoother and little to no knock underboost"

you shouldent have knock underboost anyways, if you do your seals are already gone, and i dont understand why you think this makes your car feel smoother, if anything this should make your car feel slower

 

Hell, why not jet fuel, why not nitro, why not rocket fuel?

Because your AUTOMOBILE engine was not designed for it.

I've got one thing to say: If your engine runs without knocking, buying higher octane fuel IS A WASTE OF MONEY AND WILL ACTUALLY DECREASE PERFORMANCE!
AND YES, I AM SHOUTING!

But don't take my word for it. Learn what flame front propagation is all about!

 

I kind of like the idea of a hydrogen powered wankel myself.

 

yeah, but only if mazda had the ***** to turbocharge it

 

A pressurized hydrogen powered wankel would be awesome.

 

I dont think so. I think it would be scary. Your a ticking hydrogen bomb =P.

 

you do kwno that you must tune for higher octane gas and be running more boost to get more power right???

 

wow, where to start

I know what a flame front is, how it propogates, etc
I know how octane is calculated.

I agree, if you're running the same level of boost and ignition timing, running a higher octane fuel will not increase performance. Higher octane (which is related to flame front propogation) allows you to increase those factors without as high a risk of damage to the engine (knock, detonation, preignition)

I also agree that some of Fatman's statements are incorrect. If he's feeling an increase in power with the higher octane, he might be detonating on 93 (variety of causes).

jet fuel such as JP-8 is designed for turbine engines and (from what i understand) is manufactured quite a bit different.

avgas such as 100LL is designed for use in planes such as the Cessna 172s I am currently training on. The motor is a 150 or 180 HP piston motor. 2/3 planes I have flown are flat 4s, the other is a 6 cylinder...all using the same gas. Other than damage to an O2 sensor and/or catalytic converter, I don't see how this gas should cause damage to our rotary motors or the piston motors in many high perf boats that are using the same gas.

Is there any difference in this gas and the gas VP or other suppliers sell at the track? Most 100+ and all 110 and 116 I have seen is leaded. I have also commonly heard and read people post calling this fuel "avgas"

SO, why is everyone getting excited??

I mean, hell....other people are putting paint thinner in their gas

-Nic

 

No no no , I didnt say more power. I just feel certain things less. I stutter less, less spontaneous things happen. I "heard" the high octane helps keep your injectors clean. This true as well?
EDIT: Also I mix in a bit because I get 12psi boost spikes sometimes.

 

try adding 151

i use 98 sometimes. i just feel like maybe it will burn off residue if there is any. but i definitely feel a difference. and its plenty good enough. $50 for a full tank though...

but yeah i agree that if you car is running fine, you shouldnt worry about using jet fuel...

 

There's been plenty of discussions on this topic. Avgas is not "racing fuel", and a high octane number doesn't necessarily equate to high performance in a fuel. And there is a hell of a lot more ingredients in racing fuel that determine its proper usage and power potential than just octane.

Piston/prop engines like in your Cessna are low/slow-revving motors that are made to run at specific rpms for extended periods. It's a totally different environment than an engine that's high-rpm, high-load, and needs to accelerate constantly. Without going into an extended chemistry class, fuels are blended with a specific role in mind.

Using avgas in your rotary won't damage it (other than the 02 sensor), but it's a waste, not only because if you're not tuned for it, you won't realize any power benefits, but also because the fuel is blended to burn differently. Racing fuels with a similar octane rating have a different additive package that allows them to pack more power potential per amount of fuel burned than avgas. There's been countless articles done that have proven racing fuels outperform avgas, on the dyno and on the track.

The people who are calling racing fuels like VP and Sunoco "avgas" just because the octane ratings are similar are ignorant. And there are several excellent unleaded racing fuels with octane ratings over 100.

I'm not a believer in simply adding toluene or xylene to pump gas to raise octane. Playing amateur chemist isn't my idea of ensuring that my engine is operating safely. Again, there's a lot more that goes into a high-performance racing fuel than just "raising the octane number."

 

As a pilot, I have some knoledge that might help.

AV100LL breaks down conventional motor oil. If you plan on using it, I would make sure to change the oil also.

However, the standards that apply to avgas octane isent the same as it is with regular fuel. AV100LL works out to be less then 100 octane using auto standards.

 

I think I'll just go in a corner and DRINK some paint thinner...

 

Dam it then Xelyne it is =P