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So this last weekend I did a bit of racing at the local track. A good car friend of mine that also knows his fair share said to throw a gallon of 110 leaded in to insure a high enough octane rating (our 93 isn't that great around here) and the lead would help create a tighter seal on the valves and such. I am running a Forced Performance catless down pipe so I did it. While my Cobb OTS 93 tune is plenty safe the way it is, I figured extra insurance is cheaper than any other option.

I'm looking for opinions and other points of view. Its obviously been done already and the car still runs just fine post 110 tank. Now I just have to replace the fender liners that the tires chewed up...
 

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So this last weekend I did a bit of racing at the local track. A good car friend of mine that also knows his fair share said to throw a gallon of 110 leaded in to insure a high enough octane rating (our 93 isn't that great around here) and the lead would help create a tighter seal on the valves and such. I am running a Forced Performance catless down pipe so I did it. While my Cobb OTS 93 tune is plenty safe the way it is, I figured extra insurance is cheaper than any other option.

I'm looking for opinions and other points of view. Its obviously been done already and the car still runs just fine post 110 tank. Now I just have to replace the fender liners that the tires chewed up...
Do not use leaded fuel in a vehicle with oxygen sensors or a catalyst for any meaningful duration unless you want them to clog up and fail. That's why a lot of vehicles have labels saying "Unleaded Fuel Only".

You drastically shorten the life and accuracy of an O2 sensor when you run leaded fuel. If you're a race team, and are okay with the sensor lasting for a race or so, sure, have at it. Sometimes they even last longer (but with questionable reliability). But on your street car, unless you want to be changing O2 sensors all the time, just don't do it.

As well, if you're catted, the life of your catalyst will also quickly deteriorate. It clogs up, reduces its efficiency, before eventual failure.
 

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Duration was quite short, a total of about 65 track miles, the majority at or near WOT. If I burn up an 02 sensor I'll be more pissed about the work in having to replace it then the cost to replace it.
 

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If you are worried about the quality of your 93, use something like a couple gallons of 260GTX (104 unleaded) or a can of Torco.

DO NOT run leaded fuel in a motor designed for unleaded.

You just had one for the foremost authorities on the EcoBoost platform (bugasu) tell you it was a bad idea. Ignore at your peril.
 

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Discussion Starter #7
Will not ignore, definitely won't run the 110 again then. I think I can get my hands on ms109. Not to hard.

Sent from my SAMSUNG-SM-G870A using Tapatalk
 

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You could try this stuff.The smell this fuel makes is intoxicating:)
vpc85.jpg
 

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Duration was quite short, a total of about 65 track miles, the majority at or near WOT. If I burn up an 02 sensor I'll be more pissed about the work in having to replace it then the cost to replace it.
Yeah,you have anything to worry about for a short term. It's roughly 100 hours of runtime before your sensor is usually clogged on it, so its not like you can't use one, just 100 hours is significantly shorter than the normal run time of 100x that :) Again, its a trade off, so if you feel like 100 hours of sensor for the time it takes to replace it, then you're fine. I know quite a few race teams do exactly that. But as you've alluded to, on this car changing the O2 is kind of a pain in the butt, especially if you had to do it every 100 hours ;)
 
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