Not to be a debbie downer, but from my experience if I can't get it with a breaker bar I will certainly not get it with my impact. I don't have a super great compressor but it's flows higher than my impacts are rated at.
One last thought for you, I've had to do this to a wheel nut before. Take the pipe that you put on your breaker bar and weld a >6" wide flat ~3/16" thick flat plate on the end away from the bar. Make sure that when you hold the thing up it looks like a "T". The pipe is the l section of the "T" and a flat edge of the plate creates the - section of the "T". Now place this on your breaker bar and rest the - section of the "T" on the floor, this helps create a flat place for the bar to rest so it won't shoot off to the side. Now put your tire back on and remove the jack stands. Now you can simply push on the car to try to loose the bolt. I hope that made sense.
Remember, wear safety glasses and be sure that you push in place that puts as much of the car between you and the breaker bar as possible. When you put this much force on something you never know what might go flying somewhere.
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