Running Aviation fuel

[crustodd]

Hey all,
I had a talk with a buddy of mine about "hot" fuels. My question is, would running aviation fuel which has lead in it, cause problems on an OBD i vehicle? I'm talking about running 4-5 gallons mixed with premium, not as a regular source of fuel. Would that be enough to damage a Cat. Conv.? Just curious.

[lafrad]

Anything leaded in there will kill your cat rather quickly.

there is no reason to do this if your engine doesn't ping on street gas.

If you have the ability to increase the timing for when you are at the Drag Strip or Road COurse tracks, then it will give you that extra edge. Otherwise it really just wastes a ton of money, as it doesn't add any HP.

[crustodd]

Yeah, I have a UniChip with +2 and +4 degrees positions. It's make pretty meaty torque with the +4 and hotter fuel. It's good on the setting I use for DD'ing, with 92 octane, but for off road I like a little "extra".

[5-90]

Avgas is either "fully leaded" or is "low lead" (the latter is distinguished by "LL" after the performance number.)

"Low lead" isn't really "unleaded" - but the TEL content is much lower (and I believe it's made up for with something else, I'm just not sure what offhand.) I'm not sure, but I'm inclined to think that LL will still poison a cat - it just takes longer.

I used to run 112LL in my old Bug when I wanted to scream around for a while (the engine had been thoroughly gone through, and I was able to adjust timing through a rather ingenious setup from the driver's seat. Walter did a /good/ /job/ giving me what I wanted - and more!) and I had it set up with the main fuel tank (for 88 when driving around. Switch to 112LL, clear out the lines, and pull out the stops for when I wanted to really get somewhere - there was a five-gallon piggyback tank.)

[stroked'73]

Best reason to use aviation fuel if you can is it doesn't have crappy ethanol in it!
A few folks around here run it in lawn mowers etc as well as anything they don't use on a regular basis - since it doesn't gum up. It has like a 3 year shelf life! I've been leary of running it in a car, but if you had an old one with a carb and no cat like mine, might be worth a try!! I could leave it in the tank all winter and have not a worry when I fire it up in the spring!!

[crustodd]

It also seems that I've gotten about 2 mpg better out of the added 3 1/2 gallons added to my 20 gallon tank! The engine is a bit quieter too. Crap on the cat killin' 110 doesn't have the ethanol in it either, but it's about $7.50 a gallon , the Av. gas was about $4.50. I may use 2-3 gallons of that for a "boost" when I'm goin' to the sand, but that'd fall into the category of a "treat"

[BADASYJ]

You could just eliminate the cat alltogether and get a little more power. The one thing that the leaded fuel will do is ruin your Oxygen sensor. I would unscrew the O2 sensor, screw in a plug and hang the sensor out of the way. I think it causes the CPU to think its running lean and give more fuel also.

[Jeepinscott]

The O2 sensor is an earth magnet and will attract the lead. They will last a long time, like 30k miles with the leaded fuel. They clean up very easily with carb cleaner.

[Plechtan]

Lead is magentic? News to me

[Biggrnjeep97]

Lead is magentic? News to me

lead is NOT ferritic...

[brokenujoint]

come on over to my work. I sometimes defuel lear 60's and challenger 305's when we are doing a a fuel transfer valve r/r or any internal wing repair... i could easily GIVE you 100 gallons of jet fuel if you wanna run that!...

honestly, it would work for a diesel.

[crustodd]

Hey Ujoint,
What state are you in?
crusT

[brokenujoint]

CA

[Jeepinscott]

Leaded Fuel

Wideband oxygen sensors are designed for an operational life of 100,000 miles (160,000 kms) under normal operating conditions. Replacement is required only if the sensor has failed due to unusual operating conditions, physical damage, or contamination. For example, a blown head gasket might allow silicon to enter the exhaust and contaminate the sensor. Oil burned in the combustion chamber due to leaking valve guides or rings can allow phosphorus to enter the exhaust and contaminate the sensor.

Depending on the lead contents of the used fuel, the expected service life time is:


for 0.6 g Pb/l: 20,000 km (12,000 miles)
for 0.4 g Pb/l: 30,000 km (18,000 miles)
for 0.15 g Pb/l: 60,000 km (36,000 miles)
In general, when using leaded fuel, the sensor will need to be replaced when functional problems occur, e.g. instable idle speed, driveability problems. The following tests can be done for a rough check of the sensor function:

Reasonableness of the signal check in rich exhaust gas: sensor signal should indicate rich
Reasonableness of the signal check in "free-air": sensor signal should indicate very air lean
Heater cold resistance at room temperature, with a multimeter between grey and white cable (H+, H-), and the sensor not connected to the Precision Wideband Controller, should be 2.5 to less than 10 ohms


The metal (Zirconium) is used in the nuclear industry for cladding fuel elements since it has a low absorption cross section for neutrons. Zirconium is very resistant to corrosion by many common acids and alkalis and by sea water. It is therefore used extensively by the chemical industry where corrosive agents are employed. The metal is used as an alloying agent in steel and for making surgical appliances. The metal super conducts at low temperatures and zirconium/niobium alloys are used to make superconductor magnets. Zirconium is used as a "getter" in vacuum tubes, O2 sensors, in flash bulbs for photography, in explosive primers, and in lamp filaments.