Leaded gas and ethanol aren't the same...Denso makes lead tolerant o2's anywho...I ran them on the blue car just incase I ever wanted to run a buttload of leaded gas and not have to worry about the o2's fouling out.

Also: E85/Leaded...Not comparable really other than octane rating.

I'd skip the race gas business. It's an expensive band-aid.

Go get the car tuned...then it'd run knock free on PUMP 93~.