andy585

friends i got to use STI 1998 model in india .the octane rating is 91 .can i use 100LL (100 octane low lead) aviation turbine fuel? or ,can i mix in ratio to make up to 96 octane .any advice

Chelspeed

Aircraft fuel for piston engines is often called Avgas, you can use this mixed with normal petrol to make a better octane fuel.

Aircraft turbine engines use kerosene, actually jet A1 kero is the spec for military planes. Kero is another name for what is called paraffin in UK. You cannot use this in a piston engine.

Exactly which of these you have is not clear to me. If it's 100 octane that suggests to me it's avgas, but if it says turbine fuel that suggests it's kero. I give up.

submannz

You can also run the car completely on avgas, just reset the computer after putting in the tank so the car can more easily adjust the timing to allow more advanced timing.

HHxx

Wont the lead in the avgas kill the lambda sensor and cat?

andy585

hi i just got more info this fuel 100 LL is meant for piston engined cessna aircraft and surprising it is also horizontally opposed four cylinder engine .can i us it bye?

Razor2001

Hey,

If you gas is 91 **octane** then chances are the actual RON rating is 94 - 96 RON. Octane = RON + MON / 2

So if the rating is 91 octane you should be getting the required RON rating your car needs already.

Ask the gas stations if the 91 is RON, MON or OCTANE.

Good luck but I am sure your gas is ok.

Cheers,
Ray

PS: I am not an expert so may want to run this by a few more peoples.

Pete Croney

You can get a lead tolerate lambda sensor and even though the LL stands for low lead, it will still clog up and kill a standard lambda sensor.

100LL is 100 RON fuel, but it isn't ideal for high revving engines. Because aircraft engines rarely go over 6,000rpm it doesn't need the burn speed of car fuel and so doesn't have it.

Racing fuel from someone like ELF would be a better bet but this is more expensive than Avgas.

submannz

You can purchase low lead and lead free race gas, yes you can't buy lead free avgas that I am ware of.

sooby

I'm not aware of any piston engine designed with aviation use in mind that doesn't need the lubrication that the leaded fuel provides.

It would be a brave man to "try it and see" ;-)

I used to fly helicopters that used the Lycoming engines. We were always told that in an emergency you could put car fuel in but that doesn't apply now because of the lack of lead content.

Besides the lambda sensor, depending on your exhaust, you'll also need to think of the catalytic converter using leaded fuels.

I only fly turbine now which, as Chelspeed has already clarified, uses JetA1.

andy585

thanks guys thats great piece of info i really appreciate .bye

John STI 8

You can get unleaded AvGas but it's only 95RON, I think it's zero sensitivity though.J

kenny.c

is'nt this atf fuel a lean burn type of fuel ??

Pete Croney

Sooby

All Rotax aviation engines are designed to run on unleaded.

sooby

Hmmmm,

Never had anything to do with them!

Carl2

Avgas (F18, 100LL) is for use in any piston engine aircraft engine. 100 octane is it's weak running rating (it's higher when running rich) I've never heard of a 94 octane Avgas, but then I only ever used F18. Jet A1 is the American military spec, but some some jets use an even higher spec (Jet A1+100 I think it is). It's basically Kerosine (diesel like, as turbines run high compressions, well over 20:1)
The UK military spec is F34 Avtur (kerosine again) although they use a slightly different spec on Aircraft carriers which has some sort of retardent added so it doesn't catch fire/explode (or something)as easily if the ship is bombed. If you want to make sure whether you have Avgas, just look at the colour. It's died a light blue colour (and smells ace) Some turbine engines can run on Avgas, but piston engines will not run on kerosine.