Aviation gas

[MMBRAZIL]

Hi, I have access to airplane gasoline, I think its 105+octane. My car has a rennsport chip, that need 95+octane. Here in Brazil gasoline in the pump has 25% alcohol. The airplane gas is 100% pure. I am planning in starting with a 50% pump 50% airplane mixture. Will the high octane do good or bad for my motor?

[dp935]

most avgas, (80 or 100 LL) is or was when i used to be around it was low lead. lead, which was the lubrication of the fuel. i ran it in a 70 nova while working at a f.b.o in the 70's.it eventually burnt the valves out of it. it might be ok using a mixture of gas though. you use to be able to purchase lead additives. sure runs good when its a straight 100LL though.

p.s. i believe in 86 all cars were built to run on non leaded fuels. so running avgas with lead now with the new design seats and valves, etc, would probably be detrimental. just my 2 cents

[swarf996]

I know people who have done this and wished the had not.

SW

[grmnxtc]

DO NOT *REPEAT* NOT USE ANY FUEL WITH LEAD IN IT, IN A VEHICLE FITTED WITH A CATALYST!!!

It will kill your catalyst in a matter of minutes/hours... and work out to be a VERY expensive fix....

High octane is good... but high octane with ANY amount of Lead is a BIG NO_NO!!!!

Clive.

[MMBRAZIL]

Thatīs what I thought about lead, specialy because the sticker says "unleaded fuel only". I beleive its unleaded, in Brazil all fuels has to be free of lead ( at least for cars ). I will check.
They told me its rated 110-115 octane.
My concerns are that here gasoline must be mixed with alcohol ( 25% ), and this makes my car run lean, witch is bad. So doing a 50/50 mixture will reduce this problem.

[MMBRAZIL]

Ok I just received the reply to my email to Petrobras. The avi gas is 100/130 octaine and has tetraetila lead aditive.
The lead is bad for the cat, but it only looses it emissions properties or will it damage the motor or performance?

[kang]

I'm not sure, but I think it can evntually clog or gum up the cat, restricting its ability to pass gas. Forgive the pun.

[MMBRAZIL]

Kang,
is there any problem in taking the cat out of the car?
I have no emission issues here in Brazil.

[swarf996]

I ran mine for years without a cat. I had a Fabspeed bypass which worked well.


SW

[MMBRAZIL]

and does it have any hp bennefit?

[swarf996]

maybe a little, I was running pump gas not avgas. I did it for the sound.

SW

[kang]

I've heard there is actually a performance hit by removing the cat. The engine needs a certain amount of backpressure. Without it, you lose low end torque.